I Tested Opus 5 vs. Fable 5. What You Need to Know.
983 segments
All right, so Claude Opus 5 is here and
if you start to look at the benchmarks,
it's really interesting because it shows
us that for a lot of things that I care
about, it's actually better than Fable
and it is half the cost of Fable.
Ultimately, Fable 5 is still Anthropic's
most impressive and, you know, strongest
model, but for a lot of these things,
you know, I've realized when I'm doing
knowledge work and when I'm building,
you know, my videos or my research or
whatever it is, Opus is more than enough
power than what I need. And when you
look at some of these charts, it's
really interesting because it shows on
things like the Frontier Bench and the
Bench and this Coding Agent Index, that
Opus is actually outperforming Fable and
it's cheaper. And this really shocked
me. So, obviously, I like to take all of
this stuff with a grain of salt. It's
fun to look at and it's good to look at,
but you want to actually get your hands
dirty and run these models through your
own actual workflows. So, today's video,
I'm just going to break down a bunch of
different experiments that I ran with
Opus 5 versus Fable 5 and break down
things like the cost, the time, and the
tokens so that you can start to
understand where you should work in
these different models within your
workflows.
All right, so pretty much all of the
experiments that I've been running today
that I'm going to show you guys, I did
within Claude Code, which means we're
comparing the models, but also inside of
the Claude Code harness. And the
variable is the same, so it doesn't
really change too much, but I did do a
few tests where I was actually in Claude
Chat and I was just, you know, seeing
how they felt without a harness wrapped
around. And let me just show you one
quick example. So, here I asked Fable 5
and Opus 5 to generate me an Excalidraw
diagram that accurately and visually
explains how semantic search with
factorization works on a large data set
for AI agents. And it's interesting here
because there's no skills it can use and
it doesn't have any context of me or,
you know, any
really way to verify. All it did was it
spit out a
um JSON file of Excalidraw for me and
then I pasted it into Excalidraw. So,
here's what we got. Fable came back with
this version over here, where we see
we've got like our indexing pipeline, we
have a large database, and it looks like
it actually misspelled this right here,
which is interesting. Large Oh, data
set. Okay, it was just like not expanded
enough. Same thing over here, vectorize.
And this is part of the whole
it had no way to verify. And as you guys
know, if you've been kind of building
agent loops and stuff, verification is
so, so important. So anyways, large data
set, we chunk it up, we vectorize it
with an embedding model.
We then get our embeddings, which is
just like the numerical representation
of the data. We put it into a vector
database here, and then we can actually
start to search. So, we've got
similarity, and that's on, you know,
points being close together. So, your
question lands here, and it would grab
the K nearest neighbors, and different
meaning is farther apart. We've got
different clusters here, and then we
come down here to the actual query. So,
if the user asks how I get my money
back, the agent searches the knowledge
base, and then it does semantic search.
It looks it up with the actual query
vectors, and we get the matches back.
So, pretty accurate. I will say though,
Opus's layout seems a bit more
organized, right? Like it's it's got
boxes, and it's got I mean, this might
not be as visual, you could argue. You
could argue that Fables was more visual,
which, you know, I think that that's
true. But this definitely feels more
organized. It feels a little bit more
detailed as well. So, that's just a very
subjective exam. A lot of the stuff that
I'm going to be talking about today is
just really opinionated and subjective,
but I'm going to still give you my
honest thoughts. So, in this example, I
think that if I wanted to teach someone,
I probably would take Opus 5's version
here. Okay, so let's start off with the
first test I ran, which was basically
giving them a huge code base, and having
them look through any bugs, and looking
through like the expected behavior, and
in some instructions like that. So, it
had to do some exploration here and help
us out, right? So, I set the goal, and I
gave it this prompt. And then, what I
did is I had Codex review the output
that Fable 5 gave us, and that Opus gave
us. So, real quick, before we look at
the results, Fable took about 11
minutes, and it cost $5.30.
Whereas, Opus here took 13 minutes, so a
little bit longer, but it was cheaper at
$4.22. You can also see the breakdown
here of input and output tokens and like
what models they use and stuff like
that. But, let me switch over to Codex
here. This is the actual result. So,
head-to-head, they both pretty much
passed everything, which is great. But,
Codex think that Fable wins here because
Fable's production patch is exactly the
one-line upstream fix, blah blah blah.
You guys can read through this if you
want. But, the final ranking here was
that Fable and Opus did similar, right?
But, Fable's was a little bit cleaner
and immediately reviewable. But, now
let's take a look at the second one. So,
I did a very similar example on the
second one where I gave them both, you
know, the same prompt, the same code
base, as you can see. Here was the repo,
here was the bug, here's example,
expected behavior, blah blah blah. So,
in this case, Opus took 20 minutes ish
and it costed us $6.50,
whereas Fable on the exact same prompt,
exact same code base, took 12 minutes
and costed us $8.73.
So, let's go see what Codex said about
these results. So, here, right, because
Fable versus Opus, we actually had Opus
perform better. Four out of four passed
right here, whereas Fable only passed
two out of four and left this
unresolved. So, the technical score for
Opus was 93 out of 95 and Fable scored
66 out of 95, which is really, really
interesting. And think about the fact
that once again, Opus in this case was
cheaper for us. The bottom line was both
agents demonstrated strong repository
navigation and independently found the
core architectural issue, but Fable's
patch is functionally close and fixes
the user-facing update bug while Opus
delivered the more accurate, thoroughly
tested, benchmark-passing
implementation. And one thing that I was
really excited to see in this release
blog from Anthropic, if I can keep
scrolling down here and find the right
spot, they basically talked about how
there was a huge improvement in Opus 5.
Okay, let me just find this real quick.
Opus 5 is much stronger at verifying its
work and iterating carefully until it
succeeds, which is huge. Like I kind of
alluded to earlier, verification has
become one of the most important things
you can do for your AI agents.
Essentially saying, "Hey, don't stop
until you hit this condition, and this
is the stopping condition. Here's how
you can test if it's actually done or
not, which basically means if you want
them to not stop until, you know, a
certain metric is hit like explicitly 10
out of 10 of this objective criteria, or
if it's something a little bit more
subjective, you can have them spin up
sub-agents that have to argue and debate
and you have to keep going until all
five of them come to a consensus or
something like that. Basically just the
ability for the AI to build something,
design tests to see if it's done or if
it's good, and then keep iterating until
the test passes. So, that's something
I've realized as I've been testing out
different models and different
harnesses. It's like, yes,
that does matter, but at the end of the
day what matters way more is how you
instruct it and how you feed context in.
So, just keep that kind of stuff in
mind.
Yes, it's good to find the best model,
but find the best model for your use
case and then understand how to talk to
the models, right?
By the way, guys, as I'm editing this
video, I just wanted to say that at the
end I go over like a snapshot of all of
these experiments and see like total
cost, total tokens, total time to run.
So, if you kind of want to skim through
the experiments, feel free. If you want
to jump to the end and see like the
total consensus, then that's there. So,
just want to let you guys know, but
let's get back to the video.
Okay, let's take a look at our next
example here. So, in this one, what I
did was I said, "Hey, {slash} goal,
build me a 10-second hyper-edited
engaging, viral-worthy announcement
video for AIS Live." So, that was our
live event that we just did. And I told
her that it could look through whatever
it wanted in my codebase and my entire
computer to figure out, you know, the
information to use.
So, let's take a look at the two
examples and how much they costed us.
So, this one was Opus, right? And I'm
going to open up this example right
here. This one actually created us a
vertical version and a landscape
version. So, let's take a look.
Okay, that was the vertical. Let me play
the landscape real quick.
>> Okay, so not bad, but not great. It only
had 10 seconds to work with, and it was
pretty fast-paced, and it honestly
looked just a little bit like
computer-y, like not super professional,
but anyways, let's see how much that
actually costed. That took 40 minutes,
and it costed $11.19.
Let's go over to Fable and see what it
did.
Okay, very cool. So, that one, you know,
they they had different sound effects,
they had different music. Also, what
you'll notice here is that some of that
was inaccurate. I don't know if you guys
want to AIS live or not, but some of
that data was outdated. Now, that's not
Fable's fault, that's probably more on
me for not keeping that context
completely updated inside of my OS. But,
if it would have been better about
verification, I'm pretty confident it
could have found the right stuff. If it
would have dug deeper into my school
community and looked for threads, if it
would have looked at some other LinkedIn
posts or other things that I've done, it
could have found out that some of that
stuff was inaccurate. of the speakers
didn't end up speaking at this event and
stuff like that. So, there was a little
bit of like a context issue there, but
as far as the actual videos,
that's what we got, right? And they're
they're different. You can tell that the
models have different taste. They were
given the exact same prompt. Opus
decided to make two, Fable decided to
make only one. So, let's take a look at
the cost of Fable. This one was
obviously, you know, about half the
cost, about $7.07.49.
Um so, Opus took a lot longer here, but
it did decide to do basically double the
output. And by the way, at the end, I'm
going to show a full breakdown of all of
the total costs, time, input, output
tokens, so just stay tuned for that.
But, let's keep flying through some of
these other experiments here. And by the
way, if you want to access this entire
free breakdown document, as well as all
the other resources that I ever give
away on YouTube for free, just go to my
free school community. The link for
that's down in the description. You'll
go to classroom, you'll go to all
YouTube resources, and then you'll find
everything in there for free. So, let's
get back to the video.
Okay, so I think you guys get the point.
All of these other experiments we're
going to do the same thing. Exact same
prompt. I'll show the cost and we'll
look at the outputs. So, this time I
asked for a one-page landing page for a
certified AI consultant program. I told
it it could look through whatever it
wanted and, you know, make it as
impressive as possible. So, let me real
quick pull up both of these outputs.
Okay, so here is the Opus output. Not
another AI course, the credential the
SMB market hires from. You can see
there's a bit of a dynamic 3D element in
the background. It pulled my logo. We
have an apply button. We can jump down
to certain sections. That's pretty cool.
If I go to the nine pillars, you can see
what this course is actually designed
around. I mean, this does look pretty
generic. It has our brand guidelines
though. It uses our colors. It uses our
logos. It uses our different buttons and
our different design kind of criteria.
And it has all of this which is, so far
what I can see, all of this is
completely accurate information based on
my meeting recordings, based on my, you
know, internal docs about this cohort.
As you can see right here, we've got
this information as well. And yeah, um
this isn't too bad. It's very wordy, but
it's also very accurate. So, let's
switch over now to Fables version of
this
and see what it did here. If I can find
where it caps this HTML, here it is. I'm
going to have to open this up in the
browser real quick. Okay, so here is
Fables version. It's very similar. We
have the card right here, which is a
nice touch because we do actually have
like a card designed very similar to
this. Not another AI course, the
credential the SMB market hires from. Um
we've got nine pillars, two layers each,
54 job posts analyzed, 50 founding
seats. Claim a founding seat. We can
keep scrolling down. So, they're very
similar style, right? This one has a
nice little animation here. They both
obviously pulled my logo and our brand
guidelines that you can see that they're
designed very similarly, which is great,
you know? Um we have other stuff here
like the disciplines, the pillars are
the same once again. I don't know. I
mean, they're they're obviously designed
very similarly. This is a nice touch
here.
I think the thing about this is
I probably would obviously want to
manually tweak both versions. They're
very similar. I don't think one
definitively beats the other. So, let's
look at the cost and the time. So, Fable
was 20 bucks and 50 cents, and it took
22 minutes, whereas Opus was
35 bucks and 83 cents and took almost an
hour. So, this is one of those cases
where
Fable was actually cheaper
and quicker, and arguably maybe just
like a little bit better, but it was
very similar on that side and very
subjective. So, maybe one conclusion we
can start to draw here is that Fable
still kind of wins on the creativity and
the design side compared to Opus 5,
whereas right now Opus 5 is kind of
having more of an edge for me on like
actually following directions,
verification. In most cases, it's going
to be cheaper once again. Okay, let's
keep on moving here. So,
experiment number three here was that I
wanted a LinkedIn post with a LinkedIn
carousel, and you can read the rest of
this post here, but basically I was
trying to raise the stakes, right? I was
trying to say, "Hey, you know, if I post
this out on my audience, um it would be
bad if this was,
you know, clearly AI-generated or
whatever." And I also had it choose the
topic. So, Opus, let's see what it
decided to do. Here is the actual PDF it
created for me as the carousel. I don't
love this styling, right? It's obviously
pretty consistent with our brand
guidelines, but it just looks a little
bit, you know, meh. It just doesn't look
super, super professional. So, that's
the carousel. It basically chose to
write about AI got dramatically better
at coding and trust in it went down. So,
let's see what the actual post looks
like. It probably used my LinkedIn
writing skill to do this. So, here is
the actual post. We've got some real
stats in here. We've got the arrows, a
reference to the actual carousel down
there, okay?
And if I go to Fable version now, let's
scroll up here. Aha, so Fable used a
different style of carousel, which I
actually like a lot more. It's kind of
like that tweet style. AI agents went
mainstream, trust didn't. So, that's
pretty interesting. It did similar
research, and they honestly both came to
a similar conclusion on, "Hey, you know,
based on Nate's audience and based on
what's going on in the space, what
should we write about?" which is pretty
interesting. But, ultimately, I like
this deliverable much better.
And I mean, honestly, I think that when
I read through these,
the actual content of LinkedIn posts are
pretty similar. As far as like which one
do I trust more? You know, I've got a
skill built around it. I've got a no AI
slop sort of skill as well. And this is
a perfect example of like writing a
LinkedIn post, generating that content,
I think even Opus 5 is overkill. Like
you could write really good content with
Sonnet, you know, Sonnet 4.5. So,
those are pretty similar. Let's look at
the cost and the time. Fable cost us
$6.17 and took about 7 and 1/2 minutes.
And Opus here cost us $8.22 and took
longer. So, another example where Fable
actually came in
cheaper and faster, which is quite
shocking to me because what that tells
us is that Opus is using so many more
tokens to actually be more expensive.
Because if Fable and Opus used the exact
same number of tokens, both input and
output, then Opus would be pretty much
exactly half the cost, but that's not
the case. So, when Opus comes in costing
more than Fable, it means that it was
way less token efficient as well, which
is a little bit concerning.
Okay, so let's just keep on moving here
though cuz obviously all of these
experiments I could run is not going to
be the exact same as when you use it.
And you know, at the end of the day,
it's a black box. You're pulling a lever
on a slot machine. So, let's move on to
Fable or sorry, the the fourth
experiment. So, here I told it to go to
my YouTube channel, pull comments, and
then say go to my school communities and
look through threads. And I want to
understand what my audience is saying,
what the pain points are, the number one
product that I could build to help solve
their pain points, and the number one
best YouTube video that would resonate
with them. So, let's open up the HTML
here for Opus. What your audience is
actually telling you, it pulled a bunch
of sources. It pulled things from, like
I said right here, if I can keep
scrolling up,
2,200 comments on YouTube, 480 school
posts, it looks like. And here's what
we've got. So, we've got an HTML. Once
again, I don't love this font in
general. I mean, this is on our brand
guidelines, but I might want to change
that cuz it just looks very typewritery.
It looks very cheap, honestly.
Anyways, we've got pain points that are
ranked, pricing and scoping, proving the
automation worked, and then inverse
cloud versus co-work, token, blah blah
blah. The number one product to build
would be the offer engine. So, a Cloud
Code skill pack plus templates that
takes a discovery call and then produces
a scoped priced offer with a working
measurement layer out the other. So, a
bunch of different skills. It tells us
why, and then the number one video to
make would be I sold an AI system to a
real business in 7 days. Real client,
real invoice. Okay? So, let's see if
Fable can do a similar type of
conclusion with what I could build. So,
once again, this thing looked through um
YouTube comments, as well as it looked
through school posts. It looked through
less school posts, though, which is
interesting. Let me pull up this HTML.
So, we have cost and token pricing,
error stuck mid-build, getting money, or
sorry, getting clients making money. It
goes over the YouTube mood, the school
mood, pain points, once again, which
don't seem to be the exact same. They're
similar, but, you know, they're not the
exact same. The number one product to
build would be the AI consultant kit.
So, very similar. A packaged client
delivery system that takes a member from
I can build automations to a business
paid me, not another how to build
course, blah blah blah. Okay? So, that's
pretty similar, and then I worked as an
AI consultant for real business, real
client, real numbers. Okay. So, these
are very, very similar results. So, this
would be a matter of which one do you
trust more, and maybe which one looked
through more data, and that's how you
could maybe trust it more. So, let's
look at the cost. Fable here spent
$10.60 and took 10 minutes, almost 11
minutes, whereas Opus spent $8.34 and
took 20 minutes. So, a little bit less
efficient, once again, from Opus, but
ultimately ended up being cheaper. Okay.
Let's move on to the fifth experiment.
I'm sorry if I'm going fast, but I also
don't want to bore you guys just like
really, really diving into all these,
because there's a lot of things to go
through, but I want to show you a kind
of a wide range of stuff. So, this fifth
one. Your job is to create me a YouTube
video outline and a slideshow, an
Excalidraw an Excalidraw style
presentation for this YouTube video. I
want you to go through past LinkedIn
posts, school posts, YouTube videos, my
AI's plus Q&A. So, there's a lot of
things to dig through. And then I
basically told it, "You are a product
manager. You're in charge of agents. You
don't do anything. You just delegate
work and you review stuff." So, that's
what I wanted. Okay. So, it created the
presentation and the outline. Let's
first look at the outline. So, context
engineering for agents. We have a cold
open. We then move into what changed,
why the terms exist, the failure modes
of context, and we get into writing,
selecting, compressing, isolating. Okay.
So, it a pretty legit outline, as you
can see here. Let's open up the actual
Excalidraw slide deck it made for us.
Okay. So, context engineering for AI
agents. Your AI agent isn't dumb. Your
context is. Bigger windows didn't help.
So,
harder to see. I like that little touch.
We've got Excalidraw style boxes here.
Um Andrej Karpathy, Anthropic. We've got
a quote right here. Attention is a
budget. And honestly, this doesn't look
very branded the way my other Excalidraw
uh presentations look. So, I'm not sure
exactly what happened here, but this
doesn't feel exactly right. Poisoning,
distraction, confusion, clash, and rot.
We've got some other stats here. So, not
too bad, right? I would obviously make
some tweaks before I would get ready to
start, you know, thinking about how I'm
going to present this, but not too bad,
especially for one pass. Okay. Let's go
ahead and see what Fable did here, what
kind of topic it shows for us. So, if I
go to it it created outline, slides, and
notes. So, I'm going to go to the
outline. Context engineering for AI
agents. Wow, very similar. Okay. So,
we've got the hook. We've got the
section-by-section outline. What bad
context is costing you, the four moves,
write, select, compress, isolate. Okay.
So, these are finding similar things,
which is pretty interesting. I mean,
it's looking through them assuming
similar data sources. So, that's kind of
good to know, right? Like, the
consistency makes me feel good. This
looks more like what my YouTube video
ones typically do look like, though. So,
that means maybe Fable did a better job
navigating into my other project and
finding the right skills because I
forgot to mention this directory was a
completely fresh one. Both of these are
working in completely fresh
environments, so it's not inside of my
Herc 2 as all of my normal things are
running. This one had 29 slides, so
quite a bit. We've got um a big story
here, which is something that happened
to us. We have these different colors
here. This one looks way more like what
I typically am trying to build. We've
got this nice visual with context rot.
Gets lost in the middle. You know, we've
got these nice visuals here. I would say
this one is definitely a better
presentation. So, once again Fable is
kind of coming in on top when it comes
to like the actual visual elements. I'm
assuming they both did verification
loops of screenshotting and you know,
validating. I like these a lot. These
are nice slides. Yeah. I like these
slides better, so definitely I think
Fable takes the cake here. Let's look at
cost. So, Fable took about 8 minutes and
cost us 40 bucks. Wow, almost 41 bucks.
For that Opus let's see an hour and 15
minutes and 33 bucks. So
I don't know. I think that Fable wins
here even though it was a little bit
more expensive because it was still more
token efficient and it was faster. Okay.
Let's go to the next one, number six.
So, this one's interesting. This one's
very interesting. I wanted to
try to show you guys some computer use
stuff. I compared it a little bit with
Codex computer use and ultimately I
still like Codex computer use. I don't
know why. Um they're very similar now
but I think because I just have this
bias you know
already for Codex computer use I don't
know. Anyways, I don't use computer use
but I do use it a lot for verification
stuff. So here I told it to use
Playwright CLI and I told it this is
something interesting, right? I told it
to go to Google and play the snake game.
So, I don't know if you guys you
obviously know like what the snake game
is
but if I come here, you can just play
snake right here, which I used to do in
class all the time. So, I told
these two models to go to Google and to
do that. I wanted it to only play five
games and screenshot the score of each
game and give us the average, right?
Okay, you know what's really weird? I
actually just noticed something.
So, I made a big whoopsies here. I I
sent this off as Fable,
but I only but I actually used Opus. And
then for the Opus run, where I thought I
was using Opus, I was using Opus. So, I
did Opus twice here, but I'm not even
going to change that cuz I want to show
you guys this.
Same exact prompt to Opus, right? Same
exact prompt to the same exact model
twice.
But, we got drastically different
results. In this first version, the one
that I thought was Fable,
1 hour and 53 minutes, 18 bucks. But,
look what I had to do here. You were
told to only run five games and give me
the average score there. I'm not sure
why you went rogue. This thing started
running like 30 different games and it
just kept running and kept running
games. It was trying to like
maximize itself, right? Here, it got an
average of 63. So, it was running
batches of five games at a time and did
that so many times. I was like, why why
are you not following my instructions,
but Opus is so much better,
but I didn't realize that they were both
Opus. So, that's just a really good
reminder that like, at the end of the
day, these things are completely
non-deterministic. You don't know what
they're going to do.
So, anyways, this Opus run, 2 hours, 18
dollars. And then, the real Opus run
that I thought was Opus from the
beginning,
um
1 hour, 10 minutes, and $10. But, this
Opus run did much better, which is
really weird. 81 25 33 21 54, which is
like so so much better than the other
one did. So, I'm not sure exactly what
happened there, but
anyways, hopefully that was kind of
interesting to you guys. Okay, so let's
take a look at this last one that I have
to show off to you guys today. So, this
one was um a bit longer, right? You can
read this if you want, but basically
what I wanted was a simulator where we
could see different like buildings and
vehicles and we could stress test them
with different weather. We could add
weights and we could even build and
design our own um
structures and then test them. And this
one's pretty interesting, right? Cuz I
gave this same prompt obviously to Fable
and to Opus, but let's take a look at
the two differences first,
and then how long they ran. So, I'm not
going to tell you which one's which yet.
Let's just take a look. So, here's the
first one. As you can see, there's a lot
going on. Like, it's a little bit
overwhelming, right? So, if they wanted
to build something that was kind of
user-friendly and not intimidating, they
failed on that front, but that's not
exactly what we asked for. We can see
the different nodes, we can see the
different beams, we can add like weights
to them, we can see if they're passing
or failing. I don't even know, like,
this is one of my first times opening,
you know, this. I just opened them both
to look at them, but I didn't use them.
We can see I can add like snow, right?
So, if I come here, and if we want to
add snow,
we can see how things are changing. And
if I add some rain,
um this is adding it to the whole thing,
gust factor, gravity.
You can see it starts to change colors
right there because there was way too
much weight on here. And as you move
this stuff,
you know, I'm not an engineer, so I'm
not going to come in here and tell you
this is completely structurally
accurate, and you could use this for,
um
you know, making sure that your stuff
isn't going to fall and hurt people.
This is a good simulation, right?
Because you can see where things are
being
put under pressure and where you need to
increase,
um some stability and stuff like that.
Now, I will say this is pretty, um
overwhelming. Like, this UI, I don't
really understand what to do, but if
someone did understand how to get in
here and how to test out this different
stuff and, you know, build their own
custom things, I could see this being
very useful. And it just goes to show
that in less than 2 hours, I already
have this POC that I could go get
feedback on and iterate on and stuff
like that. We've even got these
skyscrapers in here that we can start to
add a bunch of different, you know,
things to. So, anyways, this was the
first version. We've got a bunch of
different machines, and then you can
also build your own. So, let's take a
look at the other version.
This one's a bit more user-friendly,
right? And this one, honestly, does look
a little bit more AI-made. This looks
very like legacy software. This one
clearly looks a little bit more AI, but,
you know, the UI I wasn't too concerned
with. But, this one's a lot simpler. I
can see the different things. I can
easily add wind or snow or an earthquake
and I can see how much pressure is being
put on these different points. You can
see I can change to a skyscraper or a
school or a vehicle and we can do the
same thing once again.
And this one also makes it way simpler
for me if I wanted to build and design
my own thing. So if I wanted to add a
few nodes here, I could add one there, I
could have one there, one there, one
there, one there and then I can start to
connect these, right?
So I can connect these here and here and
here and there and here and there and
you know, put some triangles in here if
we really want to, you know, start
getting fancy and building some nice
support. So anyways, this one just makes
a bit more sense and I didn't prompt it
to say, "Hey, you know, like this should
be easy to use and people should
understand it and the UI should not be
intimidating or whatever." Um
but anyways, like I can add weight to
these different things and I can start
to really put some pressure on this
stuff and, you know, see what it's going
to do. This is saying that this one is
unstable. So anyways, which one do you
think was which?
Because this one was actually Fable and
this one was actually Opus, which
I wouldn't have expected, honestly.
Because I think this one is honestly
much more well-designed when you think
about what you're actually seeing in the
data. So let's take a look at how much
these costed us. So Fable this only took
Fable 7 minutes
and it costed us 73 bucks. So it was
just that that just goes to show how
quick Fable can really run your session
if you're not being careful. And then
when we go to Opus here, this one took
us 2 hours and 26 minutes and 112 bucks.
So clearly Opus got stuck in a different
loop or had for some reason Opus
interpreted the verification criteria a
little bit differently and it ran way
more sub-agents and it did more stress
testing on it. And maybe that just goes
to show this line that we talked about
that Claude Opus is much stronger at
verifying its own work and iterating
carefully until it succeeds. So maybe
that just goes to show that in action
right there. Because the thing is I
think that Claude Fable could have
easily designed something and built
something this level of detail and much
better, like far, far better. I've seen
Fable do things that are way more
incredible than this, and it could have,
but it just decided for some reason,
based on the way I prompted it or
whatever it was, it just decided to be
done. It decided to be done here, which
as you guys know if you played with
Fable, it's capable of so much more. But
I think that that's a really good
reminder of the fact that once again,
these models are not deterministic, but
also that
Opus 5 interprets things different than
Opus 4.8 and interprets things different
than Fable 5, which means the first
thing that I did when I got Opus 5 is I
ran my skills. I ran my regular
workflows. I ran my regular things that
I do, you know, generating some YouTube
stuff and helping me out because I
wanted to see how it feels. That's why I
always say I take these benchmarks with
a grain of salt because it matters way
more about how you talk to it and how it
feels and how you prompt for
verification and all of that kind of
stuff. Okay, so here are the
consolidated results from those sessions
that I just showed you guys. Keep in
mind, I accidentally ran 10 with Opus
and eight with Fable. It should have
been nine and nine, but either way, the
numbers are still pretty telling. Look
at this. Opus 5 spent more, which once
again means that it's
more inefficient,
or I could have just said less
efficient, with spending tokens because
Opus 5, per token, is half the cost of
Fable 5. So for it to be more expensive
means that it's using way more tokens.
We can see the combined output tokens
right here, 2 million for Opus and
832,000 for Fable. We can see the active
time for Opus was 630 minutes, so an
average of an hour for all of these
sessions, whereas an average of about 25
minutes for the Fable sessions. Here's
the total. Now, we can see on the output
speed, we have some stats here with Opus
and with Fable, the cost per minute with
Opus and Fable, the cost per 1,000
output tokens, Opus and Fable, API calls
per session, and tool calls per session.
And just a breakdown of where the money
went. So, it's a pretty similar split,
right? A cache reads a lot of it, and
then we have cache write, and then we
have output and input. And on both of
these and on all of these runs, the
input was pretty minimal because it was
basically just, you know, um
creating output. And if you look at all
of the sessions from most expensive to
least expensive, it's honestly pretty
split besides the fact that Opus here
owns like the most expensive one. But
anyways, I will attach this exact
document in my free school community if
you guys really want to check out this,
you know, this data
session by session. But what I really
wanted to see was this headline up here.
This headline is super interesting to me
when it comes to the output tokens and
when it comes to the time for actually
running these models. So once again,
guys, I hope that you enjoyed this
comparison here where I showed you some
actual things that I have done. Like I
said, I rec- really recommend that you
just get in here with Opus 5 and you run
your skills and just see what feels good
and what doesn't. Have it do some
verification loops and see if you like
the way that Opus feels as an
orchestrator. I still personally like
the feeling of having Fable being an
orchestrator and I like to say something
like you shouldn't be writing any code
or executing anything. You should just
be telling Opus what to do and that
saves your session limit with Fable big
time because you can be running Fable
for multiple hours or even a day and it
won't even hit like 300k or 400k on the
context because all it's doing is
delegating. So try out that tip, but
also, you know, start using Opus for
that because I think a lot of us don't
realize how powerful like a an older
Sonnet model really is that you could
use that to drive most of your daily
knowledge work. And sometimes Opus 5 and
Fable 5 are both overkill. So really
think about what you're doing and
matching the intelligence of the model
with the intelligence needed for the
task. But anyways, I hope you guys
enjoyed this video. I hope you found it
insightful and if you did, please give
it a like. It helps me out a ton. And as
always, I appreciate you guys making it
to the end of the video and I'll see you
on the next one. Thanks, everyone.
>> Mhm.
Ask follow-up questions or revisit key timestamps.
The video provides a detailed, practical comparison between Claude Opus 5 and Fable 5 through a series of real-world experiments, including coding tasks, content generation, and data analysis. While benchmarks suggest Opus 5 is highly competitive and cost-effective, the user's hands-on tests reveal that performance is highly dependent on task-specific prompting, verification strategies, and the non-deterministic nature of the models. The video concludes that Fable 5 often excels in creative and design-oriented tasks, while Opus 5 demonstrates impressive rigor in verification and complex iterative processes, ultimately advising viewers to match model capabilities with specific task requirements.
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