Opus 5 is currently #1 on Artificial Analysis Intelligence Leaderboard

(artificialanalysis.ai)

141 points | by aarondong 6 hours ago

13 comments

  • andy99 2 hours ago
    #1 in a very close race is way less useful when you have to walk on eggshells to avoid triggering censorship (“safeguards”) that either refuse or knock it down to another model. I’ve almost completely stopped using Claude (except some legacy workflows) for this reason, reliability matters more than scoring 61 instead of 57. To me Claude is the most compromised and unreliable model (between the censorship and the id checking - which I have not experienced personally), it’s not worth whatever slight benchmaxxing they did for the latest release.
    • afavour 2 hours ago
      What are you asking that you’re so regularly running into censorship?
      • areoform 30 minutes ago
        Things Fable's classifier has flagged, a non-exhaustive list,

            – "Does collagen supplementation empirically work?"
            - "Can you help me figure out how to calculate and generate Kaplan-Meier curve?"
            – "Why do rabbits reproduce so frequently?"
            — "Can you tell me how collagen peptides are absorbed by my digestive tract and the role they play? Can you teach me this works at the biomolecular level?"
        • alightsoul 17 minutes ago
          Oh biology! It's dangerous!
      • alain_gilbert 1 hour ago
        The other day, I told claude that my physical wifi door unlock push buttons is a security risk because someone could run away with it and then unlock the door from outside whenever he wants. Then I told it that I want to introduce a concept of public/private key to uniquely identify my push buttons so that I can disable them individually using some crypto like ed25519...

        Fable understood it as something along the lines of:

        "introducing" "security risk" "using software" to "unlock door" YOU ARE FLAGGED

        • JumpCrisscross 17 minutes ago
          > Fable understood it as

          The dumbfuck bouncer Anthropic put in front of Fable decided this.

          Fable is a PR model. It’s great. But if it were an employee, it would be the one who randomly shows up to work high.

      • gck1 1 hour ago
        Reverse engineering. Codex sometimes displays an advisory prompt when classifier trips - "Wait longer while we evaluate this request further or use a dumber model". If you do nothing, it'll just take some time and almost always succeed.

        It does require some brainwashing of the model to get it to the state where model itself agrees to do RE work though. But at least it's all predictable.

      • d-m 43 minutes ago
        I took a photo of a rose bush and asked “what’s going on with this rose bush” which triggered a downgrade to Opus. It diagnosed it with rose rosette disease.
      • wild_egg 2 hours ago
        I'm doing a bunch of x86_64 assembly these days and Fable is simply not allowed to debug it. Hoping Opus 5 has a bit more freedom.
        • Retr0id 2 hours ago
          I haven't been using it for long, but so far the refusals seem about on par with how things were on Opus 4.8.
      • JumpCrisscross 18 minutes ago
        I wanted to explore some battery chemistry with Fable. It decided I was a terrorist, and then blew my session’s usage credits telling me to fuck off.

        The current state of guardrails seems to be entirely about marketing to investors at the cost of customers. I’m switching to open models when my subscription expires.

      • msp26 2 hours ago
        Asking fable to read it's own model card triggers this btw. Or asking if mitochondria is the powerhouse of the cell.
        • skinfaxi 1 hour ago
          Wait wtf. The mitochondria thing is true.

          > Why this chat was flagged This model has safety measures that flag specific phrases. This can happen to safe, normal chats.

          > Your message itself appears to be what’s triggering the safety check. Editing it and retrying may help.

          • cge 46 minutes ago
            There’s confusion about the classifiers on Fable. They don’t ban chemistry and biology topics they flag as a potential risk, they ban anything related to chemistry or biology at all. This is intentional, and directly stated on the model card, but seems so absurd that there can be assumption it must be a misreading.

            Being a researcher somewhat connected to chemistry and biology, Fable has been the most useless model I have ever tried. Essentially all work has instantly downgraded to Opus.

          • stavros 1 hour ago
            Anything biology-related does this. It even did it when I asked it how eye color works, or something about frogs.
            • estearum 53 minutes ago
              Probably because the cost of blocking "is mitochondria the powerhouse of the cell" is nearly zero, while the cost of allowing "how do I synthesize the Spanish flu" is approximately infinite.
              • areoform 35 minutes ago

                    >  while the cost of allowing "how do I synthesize the Spanish flu" is approximately infinite
                
                I've heard this sentiment repeated elsewhere, but why? What makes you think that's the case?

                Under this rationale, every serious HS textbook has "approximately infinite" risk. That's clearly not so. Why is this any special?

                • estearum 29 minutes ago
                  Does every serious HS comp sci textbook give aspiring software engineers the same power that e.g. Claude Code does?
        • Mistletoe 1 hour ago
          Gemini knocks this out of the park, Gemini gang unite.

          https://share.gemini.google/34vZzlnsmTaL

      • rzk 30 minutes ago
        I had a long session about SQL with Fable and at some point, it started to falsely trigger censorship for any message I write in that conversation, even for the simple string: "random message."
      • wewtyflakes 2 hours ago
        I've hit it with intensely benign things; like asking it to make me a web-based client-side word game. I am guessing it saw the dictionary and pattern matched on various words, though ultimately it provided no explanation for why it triggered safeguards.
      • fluidcruft 1 hour ago
        I haven't had a chance to try Opus 5 yet but Fable currently refuses to do anything in my field (radiology image analysis). It didn't used to be that way but that has been the reality the last two weeks or so. Fable has been useless they might as well drop it as far as I am concerned.
      • patcon 1 hour ago
        Working on dimensionl reduction algorithms, I hit it all the time. I'm also trying to port related protocols from single-cell transcriptomics to collective intelligence systems (working with people x reaction matrices as analogous to single-cells cell x gene matrices.

        Something between single-cell work and advanced nonlinear DR methods (perhaps used in alignment work?) it always flags me

      • icedrift 2 hours ago
        If you even broach language related to biology you’ll get rerouted. I was presenting data in a grid and referred to a grid cell, Fable saw the word “cell” and safeguards kicked in
        • jefftk 2 hours ago
          I thought we were talking about Opus 5, the model Fable now falls back to?
          • eterm 1 hour ago
            This thread is full of people talking confidently about their experience with a model released just hours before.

            Either that or everyone is indeed talking across each other and talking about different things.

      • dylanowen 1 hour ago
        I was trying to debug/fix a segfault in the JVM which kept getting flagged
      • theplumber 55 minutes ago
        Fable refuses to work on a login/signup system for example.
      • weird-eye-issue 1 hour ago
        Literally anything related to nutrition, athletic performance, etc especially if you ask it for research or sources
        • AnotherGoodName 1 hour ago
          Writing an implementation of a board game and one of the cards is called "microbes". Instantly knocked down to a lower tier model whenever it encounters that keyword because clearly bioweapons. Sigh.
      • Levitz 1 hour ago
        I routinely get into blocks when running medicine-related material through it.
      • jbritton 1 hour ago
        I was flagged for basically answering yes to what Claude suggested to do, which was test commands on a port for my code for tests we had been discussing. I really think it was flagged simply because the words test and port were in the prompt. Their filters are pathetically poor.
      • arcanemachiner 1 hour ago
        I was profiling a slow machine the other day, and triggered the safeguards.

        I've been saying this a lot lately, but it doesn't bites you until it bites you.

        The more you use the clanker as a general purpose fix-it tool (goodbye manual NeoVim configuration, you will not be missed!), the more you will find yourself bumping into these safeguards.

      • thousand_nights 2 hours ago
        i do homebrewing and asked it to compare some beer yeasts for me and hit the safeguards because... biology i guess lol
      • Tostino 1 hour ago
        Trying to have it do some rework on a patch to Postgres I'm working on, it just completely shuts down. The reported issues were with privileged escalation and I was instructing it on how to fix.
      • cute_boi 1 hour ago
        Just ask math question and it will censor that. Even Misanthrophic employee confirmed that.
      • idiotsecant 43 minutes ago
        The better question is how would you not? I got demoted to opus from fable for asking if a cancer vaccine I saw on YouTube based on frog bacteria was a real thing. I've gotten it for asking how encryption works. It's incredibly touchy.
    • gck1 1 hour ago
      Every time an online chatter (e.g. "limits are better", "model is better") makes me to reevaluate my principle of never paying Anthropic, I go to the model card, which strengthens my belief in the principle.

      Why is Anthropic is so hell-bent on this auto/silent downgrade? Do they have a single user who prefers an auto-lobotomization instead of a refusal? Have they learned nothing from the backlash the first time?

      • kccqzy 1 hour ago
        Just go to /config. The very second configuration item is “Switch models when a message is flagged” and presumably you want to turn this off.

        Oh but then you said you never pay Anthropic so you haven’t actually used Claude Code yet. Why would anyone listen to the opinion of a non-user?

        • gck1 58 minutes ago
          > so you haven’t actually used Claude Code yet.

          Where do you think the principle came from? I've used claude code for a year, and stopped February this year.

      • markasoftware 1 hour ago
        I don't believe they do silent downgrades right now, they're loud about it.
    • buzzerbetrayed 2 hours ago
      Yep. I cancelled my Claude Max subscription 2 weeks ago after feeling like Anthropic was doing everything it could to fuck with my day to day. Their lead would have to become significant for me to ever go back.
    • pinkyboy 2 hours ago
      [flagged]
  • didibus 1 hour ago
    What's interesting is this:

    The top AI models by Intelligence Index are: 1. Claude Opus 5 (Adaptive Reasoning, Max Effort) (61), 2. Claude Opus 5 (Adaptive Reasoning, Xhigh Effort) (60), 3. Claude Fable 5 (Adaptive Reasoning, Max Effort, Opus 4.8 Fallback) (60), 4. GPT-5.6 Sol (max) (59), and 5. Claude Opus 5 (Adaptive Reasoning, High Effort) (59).

    Which means Opus5 at Xhigh is still smarter than Sol at max, and Opus5 at High is equal to Sol at max.

    That would make Opus5 High same as Sol max, and now I wonder what the price and speed difference between those is?

    • theplumber 21 minutes ago
      Opus5 is simply not as inteligent as Sol max. To me it looks worse than Opus 4.8 on some tasks. When I say worse I mean mainly superficial. I basically have to teach him how the whole app/framework works before he just jumps doing stupid stuff(I.e adding features already supported but in a different form)
  • chmod775 2 hours ago
    The more interesting finding is that it's still the second most expensive model (after Fable 5) by a long shot.

    At least two models (GPT-5.6, Kimi K3) match its score (~1-2% diff) for half the cost.

    • ricardobeat 2 hours ago
      The chart shows max effort, used mostly by price-insensitive enterprise users. At medium effort it drops to almost half K3’s cost, and is probably sufficient for 95% of coding tasks.
      • Bolwin 10 minutes ago
        For a fair comparison, you should compare to K3 (which AA has not tested yet unfortunately) and GPT 5.6 Sol also on medium or the closest equivalent
      • andriy_koval 18 minutes ago
        Opus medium = Sol high = 56, but still 25% more expensive
      • stingraycharles 1 hour ago
        Yeah if there’s one thing that people should really understand it’s that it’s cheaper to have smarter models with less thinking than cheaper models with more thinking.
  • firasd 3 hours ago
    Very interesting that one of the components is "AA-Omniscience Index"

    AA-Omniscience Index (higher is better) measures knowledge reliability and hallucination. It rewards correct answers, penalizes hallucinations, and has no penalty for refusing to answer.

    This seems to be a good proxy for param size/density and the ranking breaks down as such: Claude Fable 5 (with fallback), Gemini 3.1 Pro Preview, Claude Opus 5 (Max), Grok 4.6 (high), Gemini 3.6 Flash, GPT 5.6 Sol (Max)

    I've thought for a while that Gemini 3.x has 'big model smell'

    • chronogram 1 hour ago
      I'm not so sure. Especially with 3.6 Flash being 24 to Sol's 22. The 3.x Flash models were thought to fit on a single TPU 8i and it's the odd one out in that list at a whopping 234.7t/s compared to Sol's 64.4t/s and Opus's 56.3t/s. Even 3.1 Pro is a much higher 113.9t/s than the others.

      I think AA-Omniscience Accuracy follows your expectations better. An ultra size Fable at 61%, followed by large frontier models like Sol, 5.5 and Opus. With Flash being up there. I assume because Gemini is more focused on general knowledge to operational cost in particular, rather than getting the highest scores in coding benchmarks. If you go to Domain Score (Normalized) you'll see that the Gemini models are only less competitive in Software. And that's where Sol goes from 6 in Health to 71 in Software.

    • mchusma 1 hour ago
      Gemini 3.1 pro is really good for knowledge tasks. Google has done well there. And image analysis with Gemini flash 3.6 is solid. It’s just anything coding or agentic they fall short.
      • andriy_koval 5 minutes ago
        they likely tune their models for areas where they have their money: search, ads, youtube, etc.
  • aarondong 6 hours ago
    Before getting too excited, take a look at the intelligence vs cost matrix: https://artificialanalysis.ai/models?intelligence-index-toke...
    • eli 3 hours ago
      Max is lot of extra reasoning. I wonder how many fewer tasks it solves on high. I bet that costs quite a lot less.
      • emmp 2 hours ago
        Indeed, you can filter the graphs to see these the values for alternative reasoning settings of the models. Opus 5 High reasoning scored 59 on the index (exactly the same as GPT 5.6 Sol Max), and costs $1.06 per task (vs $1.04 Sol Max). So these seem essentially equivalent on both metrics.
    • midnightbobarun 6 hours ago
      5.6 Sol (max) being cheaper than all of these is wild, considering how good the output is too
      • nijave 3 hours ago
        I think on swebench verified luna was only like 3% points lower for 1/5 the cost

        Like 96% vs 93% or something

      • impulser_ 3 hours ago
        It shouldn't be surprising OpenAI does have the most compute out of all the major labs. The only reason why Anthropic models are expensive is they are the most in demand models in the world and Anthropic is fighting for compute. The only way to you limit demand for your model is increasing API pricing this is also why Anthropic probably has great margin and probably is profitable compared to OpenAI.
        • scrlk 3 hours ago
          Not just compute for OAI, GPT-5.6 is more token efficient across the board vs the Anthropic equivalents: https://artificialanalysis.ai/models?intelligence-index-toke...

          No wonder why Tibo can afford to hit the reset button liberally.

        • charcircuit 2 hours ago
          I also suspect there is a price fixing agreement between all of the inference providers for Claude (such as Amazon, Anthropic, Microsoft, etc).
          • vikramkr 57 minutes ago
            I doubt there's any sort of criminal behavior there - the model is anthropic's up and anthropic probably charges a very expensive license fee that's the same for all of them, and their cogs on compute aren't going to be wildly different, so the main drivers of the cost are roughly the same and they're all offering customers the same end product so the prices would likely also be similar in the end
            • charcircuit 28 minutes ago
              Do you really think there is nothing someone could do to make it a fraction of a percentage cheaper to serve like having access to cheaper electricity or a more mature cloud management software. Even saving a fraction of a penny on the prices can make a different due to how much volume people are paying for.
          • wmf 1 hour ago
            "Price fixing" isn't the correct term here but yes, it's very common to have the same price across different retailers/resellers.
            • charcircuit 32 minutes ago
              There is a difference between the market discovering a price and a bunch of retailers/resellers entering an agreement to sell at a specific price.
      • giancarlostoro 3 hours ago
        Probably because they made ASICs to run inference for less.
        • brookst 3 hours ago
          Are those actually deployed at scale yet?
          • brcmthrowaway 3 hours ago
            Yes.
            • wmf 3 hours ago
              I hate to disagree with Broadcom Throwaway himself but it's unlikely that the OpenAI Jalapeno ASIC has been deployed yet. It takes 6-12 months to test, develop software, ramp production, etc.
      • Schiendelman 4 hours ago
        This must be on API costs, not counting the $100/200 tiers, right?
        • anuramat 2 hours ago
          yes; fyi usage limits on the $200 claude sub correspond to at least $1.2k/week in api tokens
  • kristopolous 46 minutes ago
    I posted this before but I have a really simple shell tool to keep up with these charts over at

    https://github.com/day50-dev/aa-eval-email

    This also works

    $ curl day50.dev/art-analysis.sh | bash

    Artificial analysis knows about my tool and I'm working with them on getting their API improved.

  • nu11ptr 1 hour ago
    I don't have a horse in this race, but to me this makes GPT-5.6 Sol Max look better. It is about half the cost for nearly the exact same performance. It just goes to show how expensive Fable really is when Opus 5 is still this expensive relative to GPT 5.6.
  • zormino 2 hours ago
    I'd be curious to see the results, especially with some models having 1.5m and 2m context sizes, if the first 75% of the context was filled with unrelated info.
  • theplumber 1 hour ago
    Why do I find it dummer/even more superficial than opus 4.8? It just continued a session and I had to stop it because it become obviously “lost”
  • zuzululu 9 minutes ago
    i used for several hours now and my verdict is that its no better or worse than sol

    its surprisingly bad at UI which is unexpected

    its also lacking in depth vs sol 5.6 which goes above and beyond (which in itself is also an issue at times)

  • hoppp 2 hours ago
    I didn't like it as much as fable. The coding style was a bit different and it way overbuilt the thing I asked from it.
    • vehemenz 2 hours ago
      It’s crazy that people feel confident making judgments like these when the model’s been out for only a few hours.
  • sggyamg 2 hours ago
    It's new, normal.
    • LeBit 2 hours ago
      Wait until DeepSeek v5 Pro is released in less than a month and costs 1/100 to perform the same tasks.

      "Not fair! They distilled Opus 5!"

      • brikym 14 minutes ago
        Why doesn't Anthropic distil themselves then if that's what makes it cheaper. IMO the cost savings can't all be down to distillation.
  • claude-ai 5 hours ago
    On my end, Opus 5 is Haiku level vs. Opus 4.8 (good) and Fable (superb).

    Gets confused by permission prompts, cannot debug a failing test it caused (Opus 4.8 got it right after, without tens of rounds "thinking").

    • reilly3000 3 hours ago
      Are you using Claude Code/CoWork or an API client? I’m curious if it has different training that makes it more effective with specific instructions/ tool calling methods that are only implemented in official harnesses.
      • pixelesque 3 hours ago
        I'm curious about this too, and it's difficult to get any information about this given everyone has different setups, workflows and use-cases.

        I bizarrely had Opus 4.8 this week (in pi.dev within a podman container, using openrouter) start installing various python packages (and uv!) within the environment (not as root) when I asked it to code review some fairly basic Rust .rs files that were generally stand-alone (it did very nicely work out and write some stubs for them to build them and work out how they worked).

        It only gave up with the weird Python installing stuff when it discovered one of the Python packages needed Tensorflow.

        It seems pretty focused and persistent in continuing its initial approach, and I'm wondering if I need to alter some instructions / initial prompts to rein it in a bit...