Anthropic · launched 1 Sept 2026

Claude Fable 5.1

Released alongside the access-limited Claude Mythos 5.1. Cache reads cost 75% less than Fable 5, which Anthropic estimates cuts typical costs by about 25%.

Read the official announcement

Model details

Vendor: Anthropic
Launch date: 1 Sept 2026
Input price: $10 / 1M tokens
Output price: $50 / 1M tokens
Cached input: $0.25 / 1M tokens
Batch discount: 50%
Context window: 1M tokens
Max output: 128K tokens
Input types: Text, Image, File
API model ID: claude-fable-5-1
OpenRouter ID: anthropic/claude-fable-5.1

Compared with Claude Fable 5

Input price

$10

was $10 · Same price

Output price

$50

was $50 · Same price

Blended price

$20

was $20 · Same price

Best published results

Terminal-Bench-Science 0.1max effort · $37.9 per task · reported by Anthropic52.6%
Humanity's Last Exam (tools)xhigh effort · $2.28 per task · reported by Anthropic65.08%
Humanity's Last Exam (no tools)max effort · $2.23 per task · reported by Anthropic60.92%
CursorBench 3.2.0max effort · $9.64 per task · reported by Anthropic73.4%
AutomationBench 1.0.6max effort · $2.45 per task · reported by OpenAI31.4%
FrontierCode 1.1medium effort · $3.28 per task · reported by OpenAI50.9%
Terminal-Bench 4.0max effort · $19.5 per attempt · reported by Anthropic55.8%
FrontierCode v1.1low effort · $2.47 per task · reported by Anthropic52.8%
CursorBench 4.0max effort · $17.3 per task · reported by Anthropic51.8%
GDPval-AA v2.1max effort · $9.59 per task · reported by Anthropic1735 Elo
WANDRmax effort · $49 per attempt · reported by Anthropic68.7%
Terminal-Bench 4.0max effort · $19.5 per task · reported by OpenAI55.8%

Price compared with other models

Model	Launched	Input / 1M	Output / 1M	Cached / 1M	Blended / 1M	vs Claude Fable 5.1
GPT-6 LunaOpenAI	22 Sept 2026	$0.10	$0.50	$0.01	$0.20	99% cheaper
GPT-5.6 LunaOpenAI	9 Jul 2026	$0.20	$1.20	$0.02	$0.45	98% cheaper
Claude Sonnet 5Anthropic	30 Jun 2026	$2.00	$10	$0.20	$4.00	80% cheaper
Claude Sonnet 5.5Anthropic	28 Sept 2026	$2.00	$10	$0.20	$4.00	80% cheaper
GPT-6 SolOpenAI	22 Sept 2026	$2.00	$10	$0.20	$4.00	80% cheaper
Claude Opus 5.5Anthropic	22 Sept 2026	$4.00	$20	$0.20	$8.00	60% cheaper
GPT-5.6 SolOpenAIPrice before the GPT-6 launch, from OpenAI's announcement. OpenRouter now lists $2 / $10.	9 Jul 2026	$4.00	$20	–	$8.00	60% cheaper
Claude Opus 5Anthropic	24 Jul 2026	$5.00	$25	$0.50	$10	50% cheaper
Claude Fable 5Anthropic · previous generation	9 Jun 2026	$10	$50	$1.00	$20	Same price
Claude Fable 5.1Anthropic	1 Sept 2026	$10	$50	$0.25	$20	Baseline
GPT-6 AstraOpenAI	4 Sept 2026	$10	$50	$1.00	$20	Same price

USD per million tokens, checked 2 Oct 2026 via OpenRouter. Comparison uses the blended price (3 input tokens for every output token).

Official benchmark results

Claude Fable 5.1 launch results

Reported by Anthropic on 1 Sept 2026 · exact values

Benchmark	Claude Fable 5.1	Claude Fable 5	Claude Opus 5	GPT-5.6 Sol
Terminal-Bench-Science 0.1Agentic scientific research	52.6%	24.7%	29%	22.4%
Terminal-Bench 4.0Agentic coding	55.8%	42%	52.3%	37.3%
GDPval-AA v2Knowledge work	1853 Elo	1723 Elo	1824 Elo	1711 Elo
OSWorld 2.0Computer use · partial	77.9%	72.9%	75.4%	–
OSWorld 2.0 (strict)Computer use · strict	41.7%	36.1%	39.6%	–
Humanity's Last Exam (no tools)Multidisciplinary reasoning · no tools	60.9%	57.8%	56.6%	–
Humanity's Last Exam (with tools)Multidisciplinary reasoning · with tools	65%	63.8%	63.6%	–
AutomationBenchBusiness workflows	31.4%	17.1%	26.9%	19.6%
CursorBench 3.2.0Agentic coding	73.4%	70.5%	70%	67.2%

Bold marks the best reported score in each row.
Fable 5.1 was evaluated with production safeguards enabled. Where they intervened, Fable 5.1 and Fable 5 scored zero on OSWorld 2.0 and Fable 5 scored zero on AutomationBench.
Claude Mythos 5.1, the same underlying model with access limited to vetted users, scores 60.9% on Terminal-Bench 4.0. Mythos has no public API price, so it is not tracked here.
A dash means the lab did not report a result for that model.

Source: Introducing Claude Fable 5.1 and Claude Mythos 5.1 (Anthropic)

Claude Opus 5.5 launch results

Reported by Anthropic on 22 Sept 2026 · exact values

Benchmark	Claude Opus 5.5	Claude Fable 5.1	Claude Opus 5	GPT-6 Astra	GPT-5.6 Sol
Terminal-Bench 4.0Agentic coding	66.4%	55.8%	52.3%	57.9%	37.3%
FrontierCode v1.1 (main)Agentic coding	54.4%	50.3%	48%	53.3%	47.5%
CursorBench 4.0Agentic coding	57.8%	51.8%	46.6%	–	41.7%
GDPval-AA v2.1Knowledge work	1846 Elo	1735 Elo	1708 Elo	1542 Elo	1588 Elo
AutomationBenchBusiness workflows	40%	31.4%	26.9%	41.4%	28.8%
Humanity's Last ExamMultidisciplinary reasoning · with tools	67.7%	65.6%	63.6%	57.2%	–
Terminal-Bench-Science 0.1Agentic scientific research	58.7%	52.6%	29%	64.6%	22.4%
OSWorld 2.1Computer use · partial	81.8%	80.7%	74%	–	–
ChartographyVisual chart recognition · with tools	89%	88.4%	83.4%	–	–

Bold marks the best reported score in each row.
Claude Opus 5.5 results use adaptive thinking at max effort unless noted.
Terminal-Bench 4.0 shows each model's highest score: Claude Opus 5.5 at xhigh effort and GPT-6 Astra at high effort. GPT-6 Astra and GPT-5.6 Sol figures there are as reported by OpenAI.
A dash means the lab did not report a result for that model.

Source: Introducing Claude Opus 5.5 (Anthropic)

Terminal-Bench-Science 0.1

Accuracy against cost · reported by Anthropic on 1 Sept 2026 · exact values

Terminal-based agentic scientific research tasks, in Anthropic's agentic scientific research category.

Claude Fable 5.1
Claude Fable 5

Show data table

Model	Effort	Score	Cost per task
Claude Fable 5.1	low	26.3%	$11.1
Claude Fable 5.1	medium	35.7%	$14.9
Claude Fable 5.1	high	40%	$20.3
Claude Fable 5.1	xhigh	49.5%	$31.8
Claude Fable 5.1	max	52.6%	$37.9
Claude Fable 5	low	12.3%	$17.1
Claude Fable 5	medium	21.4%	$25
Claude Fable 5	high	25%	$34.3
Claude Fable 5	xhigh	23.4%	$36
Claude Fable 5	max	24.7%	$44.1

Exact values from the data published with Anthropic's announcement.
Standard error is about 3.5 to 4.5 points per model.

Source: Introducing Claude Fable 5.1 and Claude Mythos 5.1 (Anthropic)

Humanity's Last Exam, with tools

Pass rate against cost · reported by Anthropic on 1 Sept 2026 · exact values

Expert-level questions across many disciplines, answered with access to tools.

Claude Fable 5.1
Claude Fable 5

Show data table

Model	Effort	Pass rate	Cost per task
Claude Fable 5.1	low	60%	$0.52
Claude Fable 5.1	medium	62.96%	$0.67
Claude Fable 5.1	high	64.76%	$1.05
Claude Fable 5.1	xhigh	65.08%	$2.28
Claude Fable 5.1	max	65%	$3.20
Claude Fable 5	low	59.64%	$0.61
Claude Fable 5	medium	61.4%	$1.01
Claude Fable 5	high	63.16%	$1.42
Claude Fable 5	xhigh	63.52%	$1.92
Claude Fable 5	max	63.8%	$3.44

Exact values from the data published with Anthropic's announcement.

Source: Introducing Claude Fable 5.1 and Claude Mythos 5.1 (Anthropic)

Humanity's Last Exam, no tools

Pass rate against cost · reported by Anthropic on 1 Sept 2026 · exact values

Expert-level questions across many disciplines, answered without tools.

Claude Fable 5.1
Claude Fable 5

Show data table

Model	Effort	Pass rate	Cost per task
Claude Fable 5.1	low	53.16%	$0.30
Claude Fable 5.1	medium	55.92%	$0.46
Claude Fable 5.1	high	57.96%	$0.75
Claude Fable 5.1	xhigh	60.36%	$1.53
Claude Fable 5.1	max	60.92%	$2.23
Claude Fable 5	low	50.6%	$0.17
Claude Fable 5	medium	55.88%	$0.40
Claude Fable 5	high	56.88%	$0.62
Claude Fable 5	xhigh	57.44%	$0.91
Claude Fable 5	max	57.76%	$1.70

Exact values from the data published with Anthropic's announcement.

Source: Introducing Claude Fable 5.1 and Claude Mythos 5.1 (Anthropic)

CursorBench 3.2.0

Accuracy against cost · reported by Anthropic on 1 Sept 2026 · exact values

Evaluates coding agents on tasks taken from real Cursor sessions (earlier release than CursorBench 4.0).

Claude Fable 5.1
Claude Fable 5

Show data table

Model	Effort	Score	Cost per task
Claude Fable 5.1	low	66.2%	$2.90
Claude Fable 5.1	medium	68%	$3.53
Claude Fable 5.1	high	69.4%	$4.80
Claude Fable 5.1	xhigh	72.8%	$6.96
Claude Fable 5.1	max	73.4%	$9.64
Claude Fable 5	low	62.1%	$4.46
Claude Fable 5	medium	65.2%	$6.80
Claude Fable 5	high	66.5%	$8.77
Claude Fable 5	xhigh	68.4%	$11.7
Claude Fable 5	max	70.5%	$17.3

Exact values from the data published with Anthropic's announcement.

Source: Introducing Claude Fable 5.1 and Claude Mythos 5.1 (Anthropic)

AutomationBench 1.0.6

Score against cost · reported by OpenAI on 22 Sept 2026 · exact values

AI agents are tested on end-to-end workflows using 47 tools across sales, marketing, operations, support, finance and HR.

GPT-6 Luna
GPT-5.6 Luna
GPT-6 Sol
GPT-5.6 Sol
GPT-6 Astra
Claude Opus 5
Claude Fable 5.1

Show data table

Model	Effort	Score	Cost per task
GPT-6 Luna	low	1.2%	$0.006
GPT-6 Luna	medium	9.4%	$0.016
GPT-6 Luna	high	14.5%	$0.021
GPT-6 Luna	xhigh	12.6%	$0.025
GPT-6 Luna	max	20.7%	$0.037
GPT-5.6 Luna	low	1.8%	$0.01
GPT-5.6 Luna	medium	4.3%	$0.02
GPT-5.6 Luna	high	9.1%	$0.05
GPT-5.6 Luna	xhigh	12.9%	$0.06
GPT-5.6 Luna	max	17%	$0.07
GPT-6 Sol	low	21.2%	$0.19
GPT-6 Sol	medium	26.9%	$0.21
GPT-6 Sol	high	31.2%	$0.24
GPT-6 Sol	xhigh	33.2%	$0.27
GPT-6 Sol	max	32%	$0.34
GPT-5.6 Sol	low	11.7%	$0.31
GPT-5.6 Sol	medium	19.6%	$0.42
GPT-5.6 Sol	high	24.8%	$0.47
GPT-5.6 Sol	xhigh	26.3%	$0.54
GPT-5.6 Sol	max	28.8%	$0.67
GPT-6 Astra	low	30.3%	$1.08
GPT-6 Astra	medium	34.1%	$1.27
GPT-6 Astra	high	37.1%	$1.44
GPT-6 Astra	xhigh	39%	$1.50
GPT-6 Astra	max	41.4%	$1.73
Claude Opus 5	low	20.4%	$1.64
Claude Opus 5	medium	23.9%	$2.22
Claude Opus 5	high	20.5%	$2.27
Claude Opus 5	xhigh	25.3%	$2.71
Claude Opus 5	max	26.9%	$3.05
Claude Fable 5.1	max	31.4%	$2.45

Exact values from the data labels on OpenAI's charts. OpenAI took competitor scores from publicly available reports.
Claude Fable 5.1 ran with Claude Opus 5 as a fallback. OpenAI notes its cost omits the fallback runs (about 40% of tasks), so its real cost is higher.

Source: Introducing GPT-6 Sol and Luna (OpenAI)

FrontierCode 1.1, main set

Score against cost · reported by OpenAI on 22 Sept 2026 · exact values

AI agents write code graded on correctness and mergeability: test quality, scope discipline, code style and codebase standards.

GPT-6 Luna
GPT-5.6 Luna
GPT-6 Sol
GPT-5.6 Sol
GPT-6 Astra
Claude Opus 5
Claude Fable 5.1

Show data table

Model	Effort	Score	Cost per task
GPT-6 Luna	low	25.7%	$0.021
GPT-6 Luna	medium	35.5%	$0.053
GPT-6 Luna	high	37.3%	$0.067
GPT-6 Luna	xhigh	37.1%	$0.073
GPT-6 Luna	max	42.4%	$0.11
GPT-5.6 Luna	low	15.4%	$0.06
GPT-5.6 Luna	medium	25.7%	$0.13
GPT-5.6 Luna	high	35.9%	$0.23
GPT-5.6 Luna	xhigh	38.9%	$0.31
GPT-5.6 Luna	max	39.8%	$0.37
GPT-6 Sol	low	37.3%	$0.45
GPT-6 Sol	medium	45.9%	$0.80
GPT-6 Sol	high	47.7%	$1.08
GPT-6 Sol	xhigh	48.4%	$1.37
GPT-6 Sol	max	49.3%	$2.14
GPT-5.6 Sol	low	35.4%	$1.89
GPT-5.6 Sol	medium	39.9%	$2.69
GPT-5.6 Sol	high	45.1%	$3.48
GPT-5.6 Sol	xhigh	46.8%	$4.15
GPT-5.6 Sol	max	47.5%	$5.19
GPT-6 Astra	low	45.3%	$1.70
GPT-6 Astra	medium	48.8%	$2.43
GPT-6 Astra	high	50.9%	$3.01
GPT-6 Astra	xhigh	50.6%	$3.28
GPT-6 Astra	max	53.3%	$4.59
Claude Opus 5	low	41.9%	$2.68
Claude Opus 5	medium	53.4%	$4.31
Claude Opus 5	high	48%	$7.24
Claude Opus 5	xhigh	43.6%	$9.14
Claude Opus 5	max	48%	$11.4
Claude Fable 5.1	low	49.8%	$2.38
Claude Fable 5.1	medium	50.9%	$3.28
Claude Fable 5.1	high	50.3%	$5.27
Claude Fable 5.1	xhigh	48.7%	$9.27
Claude Fable 5.1	max	50.3%	$12.8

Exact values from the data labels on OpenAI's charts. OpenAI took competitor scores from publicly available reports.

Source: Introducing GPT-6 Sol and Luna (OpenAI)

Terminal-Bench 4.0

Accuracy against cost · reported by Anthropic on 22 Sept 2026 · exact values

Measures how well a model completes complex, multi-step professional tasks within a command line interface.

Claude Opus 5.5
Claude Fable 5.1
Claude Opus 5
GPT-6 Astra
GPT-5.6 Sol

Show data table

Model	Effort	Score	Cost per task
Claude Opus 5.5	low	38.5%	$1.29
Claude Opus 5.5	medium	57.6%	$2.94
Claude Opus 5.5	high	64.2%	$3.88
Claude Opus 5.5	xhigh	66.4%	$7.35
Claude Opus 5.5	max	64.8%	$11.2
Claude Fable 5.1	low	40.2%	$5.70
Claude Fable 5.1	medium	43.4%	$7.80
Claude Fable 5.1	high	49.4%	$10.5
Claude Fable 5.1	xhigh	51.3%	$15.8
Claude Fable 5.1	max	55.8%	$19.5
Claude Opus 5	low	28.5%	$4.25
Claude Opus 5	medium	41.2%	$7.00
Claude Opus 5	high	47%	$10.6
Claude Opus 5	xhigh	50.6%	$13.5
Claude Opus 5	max	52.3%	$15.8
GPT-6 Astra	low	49.7%	$4.95
GPT-6 Astra	medium	53.9%	$6.15
GPT-6 Astra	high	57.9%	$7.21
GPT-6 Astra	xhigh	57.6%	$7.48
GPT-6 Astra	max	56.7%	$10.3
GPT-5.6 Sol	low	7.9%	$1.46
GPT-5.6 Sol	medium	20.9%	$2.69
GPT-5.6 Sol	high	26.1%	$4.12
GPT-5.6 Sol	xhigh	28.5%	$5.39
GPT-5.6 Sol	max	37.3%	$7.89

Exact values from the data published with Anthropic's announcement.
GPT-6 Astra and GPT-5.6 Sol figures are as reported by OpenAI.

Source: Introducing Claude Opus 5.5 (Anthropic)

FrontierCode v1.1, main set

Accuracy against cost · reported by Anthropic on 22 Sept 2026 · exact values

Measures whether an agent's code changes would be merged.

Claude Opus 5.5
Claude Fable 5.1
Claude Opus 5
GPT-6 Astra
GPT-5.6 Sol

Show data table

Model	Effort	Score	Cost per task
Claude Opus 5.5	low	47.3%	$0.40
Claude Opus 5.5	medium	54.64%	$0.80
Claude Opus 5.5	high	53.99%	$1.09
Claude Opus 5.5	xhigh	51.42%	$2.25
Claude Opus 5.5	max	54.43%	$6.19
Claude Fable 5.1	low	52.8%	$2.47
Claude Fable 5.1	medium	50.91%	$3.28
Claude Fable 5.1	high	50.34%	$5.27
Claude Fable 5.1	xhigh	48.73%	$9.27
Claude Fable 5.1	max	50.28%	$12.8
Claude Opus 5	low	41.95%	$2.64
Claude Opus 5	medium	53.38%	$4.61
Claude Opus 5	high	47.99%	$7.62
Claude Opus 5	xhigh	43.65%	$8.99
Claude Opus 5	max	48.04%	$12.3
GPT-6 Astra	low	45.27%	$1.59
GPT-6 Astra	medium	48.83%	$2.28
GPT-6 Astra	high	50.94%	$2.85
GPT-6 Astra	xhigh	50.62%	$3.10
GPT-6 Astra	max	53.26%	$4.36
GPT-5.6 Sol	low	35.44%	$1.75
GPT-5.6 Sol	medium	39.93%	$2.50
GPT-5.6 Sol	high	45.06%	$3.25
GPT-5.6 Sol	xhigh	46.84%	$3.88
GPT-5.6 Sol	max	47.49%	$4.85

Exact values from the data published with Anthropic's announcement.

Source: Introducing Claude Opus 5.5 (Anthropic)

CursorBench 4.0

Accuracy against cost · reported by Anthropic on 22 Sept 2026 · exact values

Evaluates coding agents on ambiguous, multi-file tasks taken from real Cursor sessions.

Claude Opus 5.5
Claude Fable 5.1
Claude Opus 5
GPT-5.6 Sol

Show data table

Model	Effort	Score	Cost per task
Claude Opus 5.5	low	43.7%	$1.18
Claude Opus 5.5	medium	52.5%	$2.90
Claude Opus 5.5	high	56%	$3.97
Claude Opus 5.5	xhigh	56%	$6.99
Claude Opus 5.5	max	57.8%	$13.4
Claude Fable 5.1	low	45.1%	$5.44
Claude Fable 5.1	medium	46.8%	$7.05
Claude Fable 5.1	high	49.2%	$9.08
Claude Fable 5.1	xhigh	51.6%	$13
Claude Fable 5.1	max	51.8%	$17.3
Claude Opus 5	low	40.7%	$4.87
Claude Opus 5	medium	43.3%	$6.94
Claude Opus 5	high	44.7%	$9.00
Claude Opus 5	xhigh	46.1%	$11.4
Claude Opus 5	max	46.6%	$11.9
GPT-5.6 Sol	low	24.6%	$0.87
GPT-5.6 Sol	medium	31.1%	$1.77
GPT-5.6 Sol	high	35.7%	$2.85
GPT-5.6 Sol	xhigh	37.7%	$4.40
GPT-5.6 Sol	max	41.7%	$8.23

Exact values from the data published with Anthropic's announcement.

Source: Introducing Claude Opus 5.5 (Anthropic)

GDPval-AA v2.1

Elo against cost · reported by Anthropic on 22 Sept 2026 · exact values

Artificial Analysis's evaluation of agents on real-world professional work across 44 occupations.

Claude Opus 5.5
Claude Fable 5.1
Claude Opus 5
GPT-6 Astra
GPT-5.6 Sol

Show data table

Model	Effort	Elo	Cost per task
Claude Opus 5.5	low	1224 Elo	$0.21
Claude Opus 5.5	medium	1576 Elo	$0.86
Claude Opus 5.5	high	1692 Elo	$1.54
Claude Opus 5.5	xhigh	1820 Elo	$4.21
Claude Opus 5.5	max	1846 Elo	$8.92
Claude Fable 5.1	low	1450 Elo	$1.41
Claude Fable 5.1	medium	1536 Elo	$2.17
Claude Fable 5.1	high	1617 Elo	$3.43
Claude Fable 5.1	xhigh	1721 Elo	$7.09
Claude Fable 5.1	max	1735 Elo	$9.59
Claude Opus 5	low	1294 Elo	$0.58
Claude Opus 5	medium	1476 Elo	$1.36
Claude Opus 5	high	1581 Elo	$3.03
Claude Opus 5	xhigh	1676 Elo	$4.96
Claude Opus 5	max	1708 Elo	$6.76
GPT-6 Astra	low	1366 Elo	$0.85
GPT-6 Astra	medium	1468 Elo	$1.82
GPT-6 Astra	high	1485 Elo	$2.43
GPT-6 Astra	xhigh	1516 Elo	$3.04
GPT-6 Astra	max	1542 Elo	$4.53
GPT-5.6 Sol	low	1289 Elo	$0.27
GPT-5.6 Sol	medium	1403 Elo	$0.60
GPT-5.6 Sol	high	1480 Elo	$1.11
GPT-5.6 Sol	xhigh	1548 Elo	$1.70
GPT-5.6 Sol	max	1588 Elo	$2.81

Exact values from the data published with Anthropic's announcement.

Source: Introducing Claude Opus 5.5 (Anthropic)

WANDR

Accuracy against cost · reported by Anthropic on 22 Sept 2026 · exact values

Perplexity's benchmark measuring agents on large data collection tasks.

Claude Opus 5.5
Claude Fable 5.1
Claude Opus 5

Show data table

Model	Effort	Score	Cost per task
Claude Opus 5.5	low	31.2%	$1.20
Claude Opus 5.5	medium	62.8%	$11.2
Claude Opus 5.5	high	67.3%	$16.9
Claude Opus 5.5	xhigh	71.3%	$29.1
Claude Opus 5.5	max	72.3%	$37.9
Claude Fable 5.1	low	63.3%	$23.3
Claude Fable 5.1	medium	64.5%	$27.4
Claude Fable 5.1	high	66.7%	$33.6
Claude Fable 5.1	xhigh	67.7%	$42.8
Claude Fable 5.1	max	68.7%	$49
Claude Opus 5	low	50.5%	$10.7
Claude Opus 5	medium	58.1%	$24
Claude Opus 5	high	64.6%	$43.5
Claude Opus 5	xhigh	67%	$53.8
Claude Opus 5	max	67.2%	$61.6

Exact values from the data published with Anthropic's announcement.
Claude models ran with offline web search and fetch tools and a 980K-token task budget. This differs from Perplexity's published setup, so scores are not comparable with Perplexity's leaderboard.

Source: Introducing Claude Opus 5.5 (Anthropic)

Terminal-Bench 4.0

Accuracy against API cost · reported by OpenAI on 9 Sept 2026 · exact values

Tests agents on complex terminal-based tasks, including software engineering, system configuration and data analysis.

GPT-6 Astra
GPT-5.6 Sol
Claude Fable 5.1
Claude Fable 5
Claude Opus 5

Show data table

Model	Effort	Accuracy	Cost per task
GPT-6 Astra	low	49.7%	$4.95
GPT-6 Astra	medium	53.9%	$6.15
GPT-6 Astra	high	57.9%	$7.21
GPT-6 Astra	xhigh	57.6%	$7.48
GPT-6 Astra	max	56.7%	$10.3
GPT-5.6 Sol	low	7.9%	$1.46
GPT-5.6 Sol	medium	20.9%	$2.69
GPT-5.6 Sol	high	26.1%	$4.12
GPT-5.6 Sol	xhigh	28.5%	$5.39
GPT-5.6 Sol	max	37.3%	$7.89
Claude Fable 5.1	low	40.2%	$5.70
Claude Fable 5.1	medium	43.4%	$7.80
Claude Fable 5.1	high	49.4%	$10.5
Claude Fable 5.1	xhigh	51.3%	$15.8
Claude Fable 5.1	max	55.8%	$19.5
Claude Fable 5	max	44.5%	$22.2
Claude Opus 5	max	52.6%	$18.4

Exact values from the data labels on OpenAI's charts. OpenAI took competitor scores from publicly available reports.
Claude Fable 5 and Claude Opus 5 are shown at max effort only, as published.

Source: GPT-6 Astra: The next generation in intelligence for work (OpenAI)