MA
Everything has been solvedMatthew Berman10 Oct 2026
Model used alongside GPT-6 Pro by Will Depue to categorize math discoveries by whether humans or AI made them.
F5
Fable 5.1
Previous-generation frontier Anthropic Claude model, referenced as a benchmark comparison for newer Opus releases.
Updated EU status checked Last shown
Fable 5.1 at a glance
- What is Fable 5.1?
- Fable 5.1 is a model. Previous-generation frontier Anthropic Claude model, referenced as a benchmark comparison for newer Opus releases.
- Does Fable 5.1 work in the EU?
- Unverified. No explicit evidence found. Last verified 14 Nov 2026.
- How much does Fable 5.1 cost?
- Pricing unknown. Creators say it is more expensive than Opus 5.5; no exact pricing found.
- Where was Fable 5.1 shown?
- In 9 creator videos by Matthew Berman, AI Search, Matt Wolfe. Most recently by Matthew Berman on 10 Oct 2026, at 12:15 in “Everything has been solved”.
Sources: creator videos at the linked timestamps. EU status is information, not legal advice; see how we check.
About
Fable 5.1 appears to be an earlier frontier model from Anthropic. It is known here only through creator commentary, with no official page available. Creators describe it as the previous best Claude model, used as a comparison point when newer Opus 5.5 benchmarks were presented.
According to those videos, it is more expensive and more restrictive than Opus 5.5. Opus 5.5 reportedly beats it on most self-reported benchmarks, though Fable 5.1 ranks slightly higher on LiveBench. An Anthropic guest was said to describe it as suited to planning, code review and high-stakes security tasks. It was also reportedly used by Will Depue, alongside GPT-6 Pro, to categorize math discoveries by whether humans or AI made them.
Official details such as release date, context window, modalities, pricing and access routes could not be verified from the material provided, so those fields are left unknown. The vendor attribution rests on creator statements only.
Key features
- Described as previous best Anthropic frontier model
- Reportedly suited to planning, code review and security tasks
- Ranks slightly above Opus 5.5 on LiveBench per creators
- Used for categorizing math discoveries by human or AI origin
12 moments
As seen on YouTube
Watch the moment: the exact second top creators show it. Videos load only when you press play, via youtube-nocookie.com.
AI
Claude Opus 5.5 is ridiculousAI Search24 Sept 2026
Previous best Claude model, more expensive and restrictive than Opus 5.5; Opus 5.5 beats it on most self-reported benchmarks, though Fable ranks slightly higher on LiveBench.
MA
Anthropic went CRAZY (Opus 5.5)Matthew Berman23 Sept 2026
Previous frontier Anthropic model, used as a comparison in benchmarks. The Anthropic guest says it suits planning, code review and high-stakes security tasks.
AI
GPT 6 Astra, Claude Fable 5.1, Gemini 3.8, realtime Minimax, new world models: AI NEWSAI Search6 Sept 2026
Anthropic's newest model, strong at agentic scientific research, coding and knowledge work and top of an independent leaderboard. The creator flags very high cost, rapid usage-limit exhaustion and fallback to Opus 5 on research prompts.
AI News: The Most Insane Week So Far This Year!
New Anthropic model that topped benchmarks on release and still leads Artificial Analysis. Claimed 25% cheaper than Fable 5, but Artificial Analysis shows it as the most expensive per task ($3.69). The Megabonk clone looked good but cost about $120 and took 2 hours.
MA
ASTRA IS HERE (GPT-6 RELEASED)Matthew Berman3 Sept 2026
Competing model released about a day earlier, used as the comparison point in benchmarks. It scored 87.8 on FrontierMath Tier 4 and 67% on Deep Sweep, behind GPT-6 Astra.
Claude Fable 5.1 is savage
Anthropic's new top model, tested in Claude Code on 3D interior design, ray tracing, Blender, video creation, music and more. Strong on 3D, ray tracing and design, weaker on Blender, finding the frog, and tumor identification. Creator criticizes cost, slowness, usage limits and fallback to Opus 5 on biology prompts.
AI
Claude Fable 5.1 is savageAI Search3 Sept 2026
Fable 5.1 without guardrails, not publicly available. Anthropic reports it designed lab-working protein binders, produced a higher-resolution Venus elevation map, and sped up biology models by up to 2.5x.
Why Aren't People Talking About This Google Model?
Post-trained update of Fable 5 with fewer cybersecurity refusals, anti-distillation measures and unchanged $10/$50 per million token pricing. Tops Artificial Analysis (66 vs Opus 5's 63) but is the most expensive per task; the creator's Mega Bonk clone was excellent but cost about $114 in usage.
MA
Why Aren't People Talking About This Google Model?Matt Wolfe3 Sept 2026
Released alongside Fable 5.1 but only available to a small group of cyber defender companies.
Anthropic went CRAZY (Mythos/Fable 5.1)
New Anthropic frontier model with the same per-token pricing as Fable 5 but a 75% cache-read price cut, claimed ~25% cheaper for typical workloads. Benchmarks improved (Terminal Bench Science, Cursor Bench, computer use, GDPval). Artificial Analysis found it scores 66 but costs more per task because it uses 1.7x output tokens. Creator's tests (landscape scenes, Rubik's cube, five websites, slides) were good but behind GPT 5.6 Soul.
MA
Anthropic went CRAZY (Mythos/Fable 5.1)Matthew Berman1 Sept 2026
Same underlying model as Fable 5.1 with different guardrails. It scores higher than Fable 5.1 on Terminal Bench at every reasoning effort, up to about 5% better at max, and is slightly cheaper. Anthropic says it reward hacks less than Mythos 5.
Keep exploring
Similar AI tools
Closest neighbours by meaning, not just by category.
CF
Claude Fable 5.2
Model · Anthropic
Anthropic's top-tier Claude model for hard technical work, with cyber and biology safeguards, released November 2026.
UnverifiedLanguage Models
9 Nov 2026API
CO
Claude Opus 5
Model · Anthropic
Anthropic's Opus 5 large language model, ranked near the top of the Artificial Analysis Intelligence Index.
UnverifiedLanguage Models
Release date n/a
CF
Claude Fable 5
Model · Anthropic
Anthropic's premium Claude model for demanding technical work in coding, finance and science.
UnverifiedLanguage Models
Release date n/aAPI
CO
Claude Opus 4.8
Model · Anthropic
Anthropic's Claude Opus 4.8 large language model, offered via Claude subscriptions and the Anthropic API.
Available in EULanguage Models
Release date n/aPaid
CO
Claude Opus 4.5
Model · Anthropic
Anthropic's Claude Opus 4.5 model for agentic coding, tool use and knowledge work, available via app and API.
Available in EULanguage Models
24 Nov 2025API
CO
Claude Opus 5.5
Model · Anthropic
Anthropic's Claude Opus 5.5 model for agentic coding and knowledge work, priced lower per task than Opus 5.
UnverifiedLanguage Models
Release date n/aAPI