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Van Data Team

text model comparison

Claude Fable 5.1 vs Claude Fable 5.2

Claude Fable 5.1 and Claude Fable 5.2 are both current text models, from Anthropic. Claude Fable 5.2 is 20% cheaper per 1M input tokens than Claude Fable 5.1, $8 vs $10. On FrontierMath Tiers 1-3 (v2), Claude Fable 5.1 scores 90.2% and Claude Fable 5.2 95.1% (Epoch AI, measured November 10, 2026). Both accept 1,000,000 tokens of context.

Higher FrontierMath Tiers 1-3 (v2)
Claude Fable 5.295.1% against 90.2%
Lower price per 1M input tokens
Claude Fable 5.2$8 against $10
Newer release
Claude Fable 5.2Nov 2026 against Sep 2026

Data verified November 10, 2026 · Dataset 2026-11-10

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Side by side

Claude Fable 5.1 and Claude Fable 5.2, line by line

Prices in effect today, compared at the same tier wherever both list one. The better value in each row is highlighted.

FactClaude Fable 5.1Claude Fable 5.2
Price
Price per 1M input tokens$10$8 (better)
Price per 1M output tokens$50$40 (better)
Independent benchmarks
FrontierMath Tiers 1-3 (v2)90.2% (#6 of 43)95.1% (#1 of 43) (better)
SimpleQA Verified70.8% (#7 of 40)94% (#1 of 40) (better)
Arena Text1503 Elo (#6 of 53)Not measured
Arena WebDev1745 Elo (#5 of 48)Not measured
GPQA DiamondNot measured93.9% (#12 of 43)
Specs
ProviderAnthropicAnthropic
Release dateSeptember 1, 2026November 9, 2026
AccessAPI onlyAPI only
Context window1,000,000 tokens1,000,000 tokens
Max output128,000 tokens128,000 tokens
Inputtext, imagetext, image
Outputtexttext

Scores:Epoch AI · 2026-11-10Arena · 2026-11-10

Open both in the interactive comparison

Provider results

What the labs report

Results tables a lab published with one of its models, where it lists both Claude Fable 5.1 and Claude Fable 5.2. These are the lab's own figures, not independent measurements, and each table is read on its own: labs run benchmarks with different harnesses and budgets.

Anthropic, Claude Fable 5.2 launch table, November 9, 2026Anthropic · 2026-11-10

BenchmarkClaude Fable 5.1Claude Fable 5.2
FrontierCode 2.0best effort level per model32.4%49.1% (better)
FrontierSWE 256.3%69.9% (better)
AutomationBenchZapier31.4%51.4% (better)
Terminal-Bench-Science 0.152.6%74.6% (better)
WANDRrelaxed score68.7%82.1% (better)
OSWorld 2.1offline set, partial credit83.5%89.3% (better)
Remote Labor Index17.9%41.3% (better)
Humanity's Last Examwith tools65.6%74.2% (better)
Chartographyno tools44.8%73.4% (better)

Anthropic's table from the Claude Fable 5.2 and Mythos 5.2 announcement, each model at its highest available effort, with Anthropic's safeguards on; competitor figures come from their developers' system cards or the benchmarks' leaderboards. On FrontierCode 2.0 Fable 5.2 and 5.1 ran at xhigh effort and Gemini 4 Carbon at medium. Anthropic gives a Mythos 5.2 score for Terminal-Bench-Science only. Left out here: Anthropic's own evaluations (CVE Rediscovery, de novo binder design, RoboDojo Sim), Irregular's CyScenarioBench, where each lab's score covers different tasks, and Artificial Analysis's AA-Briefcase.

Charts

Against every current text model

Where Claude Fable 5.1 and Claude Fable 5.2 land among the current models of their task, on every independent benchmark, on price and on context.

Where each stands

On FrontierMath Tiers 1-3 (v2), Claude Fable 5.1 ranks #6 and Claude Fable 5.2 #1 of 43 current models. Each bar is the share of current models it beats: on score, price and context.

Claude Fable 5.1 and Claude Fable 5.2 among the current text models, one row per benchmark, price and context window.

Independent benchmarks

Arena Text

Claude Fable 5.1:#6of 53

1,503 Elo · ahead of 90%

Claude Fable 5.2: Not scored

Arena WebDev

Claude Fable 5.1:#5of 48

1,745 Elo · ahead of 91%

Claude Fable 5.2: Not scored

GPQA Diamond

Claude Fable 5.1: Not scored

Claude Fable 5.2:#12of 43

93.9% · ahead of 71%

FrontierMath Tiers 1-3 (v2)

Claude Fable 5.1:#6of 43

90.2% · ahead of 88%

Claude Fable 5.2:#1of 43

95.1% · ahead of 100%

SimpleQA Verified

Claude Fable 5.1:#7of 40

70.8% · ahead of 85%

Claude Fable 5.2:#1of 40

94% · ahead of 100%

Price and context

Price per 1M input tokens

Claude Fable 5.1:#55of 61

$10 · cheaper than 5%

Claude Fable 5.2:#53of 61

$8 · cheaper than 12%

Price per 1M output tokens

Claude Fable 5.1:#55of 61

$50 · cheaper than 5%

Claude Fable 5.2:#53of 61

$40 · cheaper than 12%

Context window

Claude Fable 5.1:#28of 70

1M tokens · longer than 23%

Claude Fable 5.2:#28of 70

1M tokens · longer than 23%

Scores fromArena · 2026-11-10Epoch AI · 2026-11-10

Quality against price

Arena Text · measured November 9, 2026

Claude Fable 5.1 scores 1,503 at $20 (blended price per 1M tokens). The line joins the current models no other beats on both price and Arena Text score; hover any point to name it.

Quality against priceArena Text score against price for 45 text models, Claude Fable 5.1 and Claude Fable 5.2 marked.1,2501,3001,3501,4001,4501,5001,550$0.30$1$3$10MOST ATTRACTIVE QUADRANTMedian price $3Median 1,473Blended price per 1M tokens (3 input : 1 output), log scaleArena Text (Elo)Claude Fable 5.1
Quality against price: the data
Arena Text score against price for 45 text models, Claude Fable 5.1 and Claude Fable 5.2 marked.
ModelProviderBlended price per 1M tokensArena Text (Elo)
Gemini 4 CarbonGoogle$41,526
Gemini 4 ArgonGoogle$41,522
Muse WonderMeta$81,511
Claude Opus 5.5Anthropic$81,506
Claude Fable 5Anthropic$201,504
Claude Fable 5.1Anthropic$201,503
Gemini 3.8 FlashGoogle$1.501,497
Muse Spark 1.3Meta$21,496
Claude Opus 5Anthropic$101,490
Kimi K3Moonshot Kimi$61,487
GPT-5.6 SolOpenAI$81,485
Qwen3.8-MaxAlibaba Qwen$31,484
Gemini 3.6 FlashGoogle$31,483
GLM-5.3Z.ai$2.151,483
Claude Opus 4.8Anthropic$101,482
GPT-6.1 SolOpenAI$41,482
GPT-5.5OpenAI$111,481
MiMo-V2.6-ProXiaomi MiMo$0.541,480
GPT-5.4OpenAI$5.631,475
DeepSeek-V4.1-FlashDeepSeek$0.521,475
GPT-6 AstraOpenAI$201,474
GLM-5.3-FlashZ.ai$0.241,474
Gemini 3 Flash PreviewGoogle$1.131,473
Grok 4.20xAI$1.561,472
Claude Sonnet 5.5Anthropic$41,472
GPT-5.6 TerraOpenAI$4.501,468
Grok 4.5xAI$31,466
DeepSeek-V4-ProDeepSeek$1.981,464
Claude Sonnet 5Anthropic$41,461
GPT-6 SolOpenAI$41,457
Grok 4.6xAI$31,456
Gemini 3.5 Flash-LiteGoogle$0.851,455
GPT-5.6 LunaOpenAI$0.451,453
MiMo-V2.6-FlashXiaomi MiMo$0.181,448
Step 5 PreviewStepFun$1.431,448
Grok 4.3xAI$1.561,442
Grok 4.7xAI$31,442
GPT-6 LunaOpenAI$0.201,441
Mistral Large 4Mistral AI$1.051,423
Claude Haiku 5.5Anthropic$0.201,422
GPT-4.1OpenAI$3.501,415
Inkling 2 SmallThinking Machines Lab$0.471,412
Solar Pro 4Upstage$0.521,387
GPT-4.1 miniOpenAI$0.701,383
GPT-4.1 nanoOpenAI$0.181,322

Cost

What each costs

Example workloads at each provider's listed rates, then every other rate either one lists. The cheaper figure in each row is highlighted.

The same work, priced

For 10M input and 2M output tokens, Claude Fable 5.1 costs 1.3 times as much as Claude Fable 5.2, at each provider's listed rates.

What Claude Fable 5.1 and Claude Fable 5.2 cost for the same work, at the rates each provider lists.

  • 10M input and 2M output tokens

    Claude Fable 5.1 costs 1.3× as much

    Claude Fable 5.1
    $200
    Claude Fable 5.2
    $160

  • The same, with 9M of the input tokens cached

    Claude Fable 5.1 costs 1.3× as much

    Claude Fable 5.1
    $112.25
    Claude Fable 5.2
    $89.80

  • The same, through the batch API

    Claude Fable 5.1 costs 1.3× as much

    Claude Fable 5.1
    $100
    Claude Fable 5.2
    $80
Workload or rateClaude Fable 5.1Claude Fable 5.2
Example workloads
10M input and 2M output tokens$200$160 (better)
The same, with 9M of the input tokens cached$112.25$89.80 (better)
The same, through the batch API$100$80 (better)
Other listed rates
1M input tokens, cached$0.25$0.20 (better)
1M input tokens, 5-minute cache write$12.50$10 (better)
1M input tokens, 1-hour cache write$20$16 (better)
1M input tokens, batch$5$4 (better)
1M output tokens, batch$25$20 (better)

Your own bill will differ. These figures use list prices and example workloads. The AI Model Cost Audit reviews your real usage, shortlists models that score as well for each task for less, and estimates the savings.

Launch price $100, regular price $150

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Verdict

When to choose each

Claude Fable 5.1

Where it leads

No measured lead over Claude Fable 5.2 in this data.

Best for

  • Long-horizon agentic coding where a large prompt prefix is replayed across many turns
  • Work where Claude Opus 5 at higher effort has already been evaluated and fell short

Watch out for

  • Base input and output pricing is unchanged from Fable 5 at $10 / $50; the saving is entirely in cache reads, so a workload with little cache reuse sees no discount
  • The 4.7-generation tokenizer produces roughly 30% more tokens for the same text than Claude Sonnet 4.6 and earlier, so per-token rates are not directly comparable across generations
  • Anthropic’s launch comparisons are self-reported and were not reproduced independently here
  • Claude Fable 5.2 (November 9, 2026) costs less at $8 input and $40 output per 1M tokens, and Anthropic now lists Fable 5.1 among its legacy models
Full Claude Fable 5.1 profile

Claude Fable 5.2

Where it leads

  • Lower input and output prices, $8 and $40 vs $10 and $50 per 1M tokens
  • Higher FrontierMath Tiers 1-3 (v2) score, 95.1% vs 90.2%
  • Higher SimpleQA Verified score, 94% vs 70.8%
  • Cheaper cached input, $0.20 vs $0.25 per 1M tokens
  • Cheaper batch processing, $80 vs $100 for 10M input and 2M output tokens

Best for

  • The hardest open-ended coding, research and agent runs, where Claude Opus 5.5 at high effort falls short
  • Advising or orchestrating cheaper Claude models in a multi-agent setup

Watch out for

  • Gemini 4 Carbon scores higher on AutomationBench in Anthropic's own table (53.9% against 51.4%)
  • Safety classifiers block most penetration testing, exploit development and research biology requests and answer them with an older model (Claude Opus 4.8 for cybersecurity, Claude Opus 5 for biology); vetted organisations use Claude Mythos 5.2 for that work
  • Anthropic recommends starting most coding and knowledge work on Claude Opus 5.5, at half the price, and moving up to Fable only when it falls short; Arena has not rated Fable 5.2 yet
Full Claude Fable 5.2 profile

From benchmark to production

Building on Claude Fable 5.1 or Claude Fable 5.2?

Public scores rarely hold on your own data. We test both models on your real tasks, then build the agent or pipeline around the one that wins.

AI Model Cost AuditLaunch price $100, regular price $150What the audit includes

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FAQ

Claude Fable 5.1 vs Claude Fable 5.2 FAQ

Which is cheaper, Claude Fable 5.1 or Claude Fable 5.2?

Claude Fable 5.2 is 20% cheaper per 1M input tokens than Claude Fable 5.1, $8 vs $10. For 10M input and 2M output tokens, Claude Fable 5.1 costs $200 and Claude Fable 5.2 $160 at standard rates.

Which is cheaper with prompt caching, Claude Fable 5.1 or Claude Fable 5.2?

Claude Fable 5.1 charges $0.25 per 1M cached input tokens, 98% below its standard input rate, and Claude Fable 5.2 $0.20, 98% below. With 9M of 10M input tokens cached and 2M output tokens, Claude Fable 5.1 costs $112.25 and Claude Fable 5.2 $89.80.

Which scores higher on independent benchmarks, Claude Fable 5.1 or Claude Fable 5.2?

Claude Fable 5.2 leads on FrontierMath Tiers 1-3 (v2), 95.1% to 90.2%; Claude Fable 5.2 leads on SimpleQA Verified, 94% to 70.8%. Scores are independent evaluations, not either vendor's launch figures.

How do Claude Fable 5.1 and Claude Fable 5.2 compare in Anthropic's own results?

In the Claude Fable 5.2 launch table (November 9, 2026), Claude Fable 5.2 leads on FrontierCode 2.0 (best effort level per model), 49.1% to 32.4%; Claude Fable 5.2 leads on FrontierSWE 2, 69.9% to 56.3%; Claude Fable 5.2 leads on AutomationBench (Zapier), 51.4% to 31.4%. These are Anthropic's figures, not independent measurements.

Which has the larger context window, Claude Fable 5.1 or Claude Fable 5.2?

Both accept 1,000,000 tokens of context. Both return up to 128,000 tokens per response.

Further reading

More on Claude Fable 5.1 and Claude Fable 5.2

Articles on Claude Fable 5.1 and Claude Fable 5.2

Related comparisons

Production evaluation

Choosing between Claude Fable 5.1 and Claude Fable 5.2?

Public benchmarks narrow the shortlist. We run both on your own tasks, data and cost limits, then build the routing and review controls to run the winner in production.

  • A head-to-head evaluation on your real workload
  • Routing between models by cost and difficulty
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