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Claude Mythos 5.1 Limited access

Anthropic Language models September 2026

Claude Mythos 5.1 is a model from Anthropic, listed under Language models. It was released in September 2026. It costs $10.00 per million input tokens and $50.00 per million output tokens. It accepts up to 1M tokens per request. Prices as of Oct 22, 2026, from the provider's official pricing page.

Only available to organisations approved by the provider.

Add to favourites Cost calculator Documentation Official pricing
Headline price
$20.00 / 1M tokens
Input
$10.00 per 1M tokens
Output
$50.00 per 1M tokens
Context window
1M tokens
Max output
128k

Current prices

ItemPrice
Input $10.00 / 1M tokens
Output $50.00 / 1M tokens
Cached input $0.25 / 1M tokens
Cache write $12.50 / 1M tokens

Checked against the provider page on Oct 22, 2026.

Price history

No price change recorded for this model yet.

How it compares

Price among Language modelsEvery available model in Language models with a comparable price. Further right costs more. Logarithmic scale: each step is ten times the last.
$0.3$1$3$10$30$100GPT-5 nano: $0.1375 / 1M tokensDeepSeek V4 Flash 0731: $0.1488 / 1M tokensGemini 2.5 Flash-Lite: $0.175 / 1M tokensGPT-4.1 nano: $0.175 / 1M tokensClaude Haiku 5.5: $0.20 / 1M tokensGPT-6 Luna: $0.20 / 1M tokensGPT-6 Luna Pro: $0.20 / 1M tokensGPT-4o Mini: $0.2625 / 1M tokensDeepSeek V4 Flash Vision Exp: $0.3234 / 1M tokensGPT-5.6 Luna: $0.45 / 1M tokensGPT-5.4 nano: $0.4625 / 1M tokensDeepSeek V4.1 Flash: $0.525 / 1M tokensGemini 3.1 Flash-Lite: $0.5625 / 1M tokensGPT-5 Mini: $0.6875 / 1M tokensGPT-4.1 Mini: $0.70 / 1M tokensMistral Large 4: $0.75 / 1M tokensGPT-3.5 Turbo: $0.75 / 1M tokensQwen3.8 27B: $0.775 / 1M tokensGemini 3.5 Flash-Lite: $0.85 / 1M tokensGemini 2.5 Flash: $0.85 / 1M tokensGemini 3 Flash: $1.13 / 1M tokensGrok Build 0.1: $1.25 / 1M tokensGemini 3.8 Flash: $1.50 / 1M tokensGemini 3.7 Flash: $1.50 / 1M tokensGemini 3.6 Flash: $1.50 / 1M tokensGrok 4.3: $1.56 / 1M tokensGrok 4.20 Reasoning: $1.56 / 1M tokensGrok 4.20 Non-Reasoning: $1.56 / 1M tokensGrok 4.20 Multi-Agent: $1.56 / 1M tokensGPT-5.4 Mini: $1.69 / 1M tokenso3-mini: $1.93 / 1M tokenso4-mini: $1.93 / 1M tokensDeepSeek V4 Pro: $1.98 / 1M tokensGPT-6.1 Terra: $2.00 / 1M tokensGPT-6.1 Terra Pro: $2.00 / 1M tokensClaude Haiku 4.5: $2.00 / 1M tokensGrok 4.7: $3.00 / 1M tokensQwen3.8 2.4T A95B: $3.00 / 1M tokensGrok 4.6: $3.00 / 1M tokensGrok 4.5: $3.00 / 1M tokensGemini Omni Flash: $3.38 / 1M tokensGPT-5: $3.44 / 1M tokensGemini 2.5 Pro: $3.44 / 1M tokensGPT-5.1: $3.44 / 1M tokenso3: $3.50 / 1M tokensGPT-4.1: $3.50 / 1M tokensClaude Sonnet 5.5: $4.00 / 1M tokensGPT-6.1 Sol: $4.00 / 1M tokensGemini 4 Argon: $4.00 / 1M tokensGPT-6 Sol: $4.00 / 1M tokensGPT-6 Sol Pro: $4.00 / 1M tokensGPT-6.1 Sol Pro: $4.00 / 1M tokensKimi K3.1 Pro: $4.00 / 1M tokensClaude Sonnet 5: $4.00 / 1M tokensGPT-4o: $4.38 / 1M tokensGPT-5.6 Terra: $4.50 / 1M tokensGemini 3.1 Pro: $4.50 / 1M tokensGPT-5.2: $4.81 / 1M tokensGPT-5.3-Codex: $4.81 / 1M tokensGPT-5.4: $5.63 / 1M tokensQwen3.8 Max Prime: $6.00 / 1M tokensClaude Sonnet 4.6: $6.00 / 1M tokensClaude Sonnet 4.5: $6.00 / 1M tokensClaude Opus 5.5: $8.00 / 1M tokensGPT-5.6 Sol: $8.00 / 1M tokensClaude Opus 5: $10.00 / 1M tokensClaude Opus 4.8: $10.00 / 1M tokensClaude Opus 4.7: $10.00 / 1M tokensClaude Opus 4.6: $10.00 / 1M tokensClaude Opus 4.5: $10.00 / 1M tokensChat Latest: $11.25 / 1M tokensGPT-5.5: $11.25 / 1M tokensGPT-4 Turbo: $15.00 / 1M tokensClaude Fable 5.1: $20.00 / 1M tokensGPT-6 Astra: $20.00 / 1M tokensGPT-6 Astra Pro: $20.00 / 1M tokensClaude Fable 5: $20.00 / 1M tokensClaude Mythos 5: $20.00 / 1M tokenso1: $26.25 / 1M tokenso3-pro: $35.00 / 1M tokensGPT-4: $37.50 / 1M tokensGPT-5 Pro: $41.25 / 1M tokensGPT-5.2 Pro: $57.75 / 1M tokensGPT-5.4 Pro: $67.50 / 1M tokensGPT-5.5 Pro: $67.50 / 1M tokenso1-pro: $263 / 1M tokensClaude Mythos 5.1: $20.00 / 1M tokens$20.00 / 1M tokens
Show data
ModelValue
GPT-5 nano$0.1375 / 1M tokens
DeepSeek V4 Flash 0731$0.1488 / 1M tokens
Gemini 2.5 Flash-Lite$0.175 / 1M tokens
GPT-4.1 nano$0.175 / 1M tokens
Claude Haiku 5.5$0.20 / 1M tokens
GPT-6 Luna$0.20 / 1M tokens
GPT-6 Luna Pro$0.20 / 1M tokens
GPT-4o Mini$0.2625 / 1M tokens
DeepSeek V4 Flash Vision Exp$0.3234 / 1M tokens
GPT-5.6 Luna$0.45 / 1M tokens
GPT-5.4 nano$0.4625 / 1M tokens
DeepSeek V4.1 Flash$0.525 / 1M tokens
Gemini 3.1 Flash-Lite$0.5625 / 1M tokens
GPT-5 Mini$0.6875 / 1M tokens
GPT-4.1 Mini$0.70 / 1M tokens
Mistral Large 4$0.75 / 1M tokens
GPT-3.5 Turbo$0.75 / 1M tokens
Qwen3.8 27B$0.775 / 1M tokens
Gemini 3.5 Flash-Lite$0.85 / 1M tokens
Gemini 2.5 Flash$0.85 / 1M tokens
Gemini 3 Flash$1.13 / 1M tokens
Grok Build 0.1$1.25 / 1M tokens
Gemini 3.8 Flash$1.50 / 1M tokens
Gemini 3.7 Flash$1.50 / 1M tokens
Gemini 3.6 Flash$1.50 / 1M tokens
Grok 4.3$1.56 / 1M tokens
Grok 4.20 Reasoning$1.56 / 1M tokens
Grok 4.20 Non-Reasoning$1.56 / 1M tokens
Grok 4.20 Multi-Agent$1.56 / 1M tokens
GPT-5.4 Mini$1.69 / 1M tokens
o3-mini$1.93 / 1M tokens
o4-mini$1.93 / 1M tokens
DeepSeek V4 Pro$1.98 / 1M tokens
GPT-6.1 Terra$2.00 / 1M tokens
GPT-6.1 Terra Pro$2.00 / 1M tokens
Claude Haiku 4.5$2.00 / 1M tokens
Grok 4.7$3.00 / 1M tokens
Qwen3.8 2.4T A95B$3.00 / 1M tokens
Grok 4.6$3.00 / 1M tokens
Grok 4.5$3.00 / 1M tokens
Gemini Omni Flash$3.38 / 1M tokens
GPT-5$3.44 / 1M tokens
Gemini 2.5 Pro$3.44 / 1M tokens
GPT-5.1$3.44 / 1M tokens
o3$3.50 / 1M tokens
GPT-4.1$3.50 / 1M tokens
Claude Sonnet 5.5$4.00 / 1M tokens
GPT-6.1 Sol$4.00 / 1M tokens
Gemini 4 Argon$4.00 / 1M tokens
GPT-6 Sol$4.00 / 1M tokens
GPT-6 Sol Pro$4.00 / 1M tokens
GPT-6.1 Sol Pro$4.00 / 1M tokens
Kimi K3.1 Pro$4.00 / 1M tokens
Claude Sonnet 5$4.00 / 1M tokens
GPT-4o$4.38 / 1M tokens
GPT-5.6 Terra$4.50 / 1M tokens
Gemini 3.1 Pro$4.50 / 1M tokens
GPT-5.2$4.81 / 1M tokens
GPT-5.3-Codex$4.81 / 1M tokens
GPT-5.4$5.63 / 1M tokens
Qwen3.8 Max Prime$6.00 / 1M tokens
Claude Sonnet 4.6$6.00 / 1M tokens
Claude Sonnet 4.5$6.00 / 1M tokens
Claude Opus 5.5$8.00 / 1M tokens
GPT-5.6 Sol$8.00 / 1M tokens
Claude Opus 5$10.00 / 1M tokens
Claude Opus 4.8$10.00 / 1M tokens
Claude Opus 4.7$10.00 / 1M tokens
Claude Opus 4.6$10.00 / 1M tokens
Claude Opus 4.5$10.00 / 1M tokens
Chat Latest$11.25 / 1M tokens
GPT-5.5$11.25 / 1M tokens
GPT-4 Turbo$15.00 / 1M tokens
Claude Fable 5.1$20.00 / 1M tokens
GPT-6 Astra$20.00 / 1M tokens
GPT-6 Astra Pro$20.00 / 1M tokens
Claude Fable 5$20.00 / 1M tokens
Claude Mythos 5$20.00 / 1M tokens
o1$26.25 / 1M tokens
o3-pro$35.00 / 1M tokens
GPT-4$37.50 / 1M tokens
GPT-5 Pro$41.25 / 1M tokens
GPT-5.2 Pro$57.75 / 1M tokens
GPT-5.4 Pro$67.50 / 1M tokens
GPT-5.5 Pro$67.50 / 1M tokens
o1-pro$263 / 1M tokens
Claude Mythos 5.1$20.00 / 1M tokens
Context windowTokens per request. Further right holds more. Logarithmic scale: each step is ten times the last.
10k30k100k300k1MGPT-6 Astra: 1.05MGPT-6.1 Sol: 1.05MGPT-6 Luna: 1.05MGPT-6 Sol: 1.05MGPT-5.6 Sol: 1.05MGPT-5.6 Terra: 1.05MGPT-5.6 Luna: 1.05MGPT-6 Astra Pro: 1.05MGPT-6 Luna Pro: 1.05MGPT-6 Sol Pro: 1.05MGPT-6.1 Sol Pro: 1.05MGPT-6.1 Terra: 1.05MGPT-6.1 Terra Pro: 1.05MGPT-5.4: 1.05MGPT-5.4 Pro: 1.05MGPT-5.5: 1.05MGPT-5.5 Pro: 1.05MGemini 4 Argon: 1.05MGemini 3.8 Flash: 1.05MGemini Omni Flash: 1.05MMuse Wonder: 1.05MGemini 3.5 Flash-Lite: 1.05MGemini 3.7 Flash: 1.05MDeepSeek V4 Flash 0731: 1.05MMuse Spark 1.3: 1.05MKimi K3.1 Pro: 1.05MQwen3.8 2.4T A95B: 1.05MGemini 3.1 Pro: 1.05MDeepSeek V4 Flash Vision Exp: 1.05MGemini 3.6 Flash: 1.05MGemini 3.1 Flash-Lite: 1.05MGemini 3 Flash: 1.05MGemini 2.5 Pro: 1.05MGemini 2.5 Flash: 1.05MGemini 2.5 Flash-Lite: 1.05MMuse Spark 1.1: 1.05MMuse Spark 1.2: 1.05MGPT-4.1: 1.05MGPT-4.1 Mini: 1.05MGPT-4.1 nano: 1.05MClaude Fable 5.1: 1MClaude Opus 5.5: 1MClaude Sonnet 5.5: 1MClaude Haiku 5.5: 1MGrok 4.3: 1MDeepSeek V4 Pro: 1MDeepSeek V4.1 Flash: 1MKimi K3: 1MGrok 4.20 Reasoning: 1MGrok 4.20 Non-Reasoning: 1MGrok 4.20 Multi-Agent: 1MZ.ai GLM 5.3 (on Mistral): 1MQwen3.8 27B: 1MQwen3.8 Max Prime: 1MMistral Large 4: 1MClaude Fable 5: 1MClaude Mythos 5: 1MClaude Opus 5: 1MClaude Sonnet 5: 1MClaude Opus 4.8: 1MClaude Opus 4.7: 1MClaude Opus 4.6: 1MClaude Sonnet 4.6: 1MGrok 4.7: 500kGrok 4.6: 500kGrok 4.5: 500kGPT-5.6 Cyber: 400kChat Latest: 400kGPT-5: 400kGPT-5 Mini: 400kGPT-5 nano: 400kGPT-5 Pro: 400kGPT-5.2: 400kGPT-5.2 Pro: 400kGPT-5.4 Mini: 400kGPT-5-Codex: 400kGPT-5.1: 400kGPT-5.1-Codex: 400kGPT-5.1-Codex Mini: 400kGPT-5.1-Codex-Max: 400kGPT-5.2-Codex: 400kGPT-5.3-Codex: 400kGPT-5.4 nano: 400kGrok Build 0.1: 256kMistral Medium 3.5: 256kMistral Small 4: 256kMinistral 3 14B: 256kMinistral 3 8B: 256kMinistral 3 3B: 256kCommand A: 256kCommand A Reasoning: 256kNorth Mini Code: 256kKimi K2.7 Code: 256kMistral Large 3: 256kKimi K2.6: 256kClaude Opus 4.5: 200kClaude Haiku 4.5: 200ko3: 200ko3-pro: 200kClaude Sonnet 4.5: 200kcodex-mini-latest: 200ko1: 200ko1-pro: 200ko3-deep-research: 200ko3-mini: 200ko4-mini: 200ko4-mini-deep-research: 200kgpt-oss-120b: 131kgpt-oss-20b: 131kCommand A+: 128kCodestral: 128kAya Expanse 32B: 128kCommand A Vision: 128kCommand R7B: 128kCommand R (08-2024): 128kCommand R+ (08-2024): 128kChatGPT-4o: 128kGPT-4 Turbo: 128kGPT-4 Turbo Preview: 128kGPT-4.5 Preview: 128kGPT-4o: 128kGPT-4o Mini: 128kGPT-4o Mini Search Preview: 128kGPT-4o Search Preview: 128kGPT-5 Chat: 128kGPT-5.1 Chat: 128kGPT-5.2 Chat: 128kGPT-5.3 Chat: 128ko1 Preview: 128ko1-mini: 128kCommand R: 128kCommand R+: 128kVoxtral Small: 32kGPT-3.5 Turbo: 16kbabbage-002: 16kdavinci-002: 16kAya Vision 32B: 16kcomputer-use-preview: 8kGPT-4: 8kTiny Aya Earth: 8kTiny Aya Global: 8kClaude Mythos 5.1: 1M1M
Show data
ModelValue
GPT-6 Astra1.05M
GPT-6.1 Sol1.05M
GPT-6 Luna1.05M
GPT-6 Sol1.05M
GPT-5.6 Sol1.05M
GPT-5.6 Terra1.05M
GPT-5.6 Luna1.05M
GPT-6 Astra Pro1.05M
GPT-6 Luna Pro1.05M
GPT-6 Sol Pro1.05M
GPT-6.1 Sol Pro1.05M
GPT-6.1 Terra1.05M
GPT-6.1 Terra Pro1.05M
GPT-5.41.05M
GPT-5.4 Pro1.05M
GPT-5.51.05M
GPT-5.5 Pro1.05M
Gemini 4 Argon1.05M
Gemini 3.8 Flash1.05M
Gemini Omni Flash1.05M
Muse Wonder1.05M
Gemini 3.5 Flash-Lite1.05M
Gemini 3.7 Flash1.05M
DeepSeek V4 Flash 07311.05M
Muse Spark 1.31.05M
Kimi K3.1 Pro1.05M
Qwen3.8 2.4T A95B1.05M
Gemini 3.1 Pro1.05M
DeepSeek V4 Flash Vision Exp1.05M
Gemini 3.6 Flash1.05M
Gemini 3.1 Flash-Lite1.05M
Gemini 3 Flash1.05M
Gemini 2.5 Pro1.05M
Gemini 2.5 Flash1.05M
Gemini 2.5 Flash-Lite1.05M
Muse Spark 1.11.05M
Muse Spark 1.21.05M
GPT-4.11.05M
GPT-4.1 Mini1.05M
GPT-4.1 nano1.05M
Claude Fable 5.11M
Claude Opus 5.51M
Claude Sonnet 5.51M
Claude Haiku 5.51M
Grok 4.31M
DeepSeek V4 Pro1M
DeepSeek V4.1 Flash1M
Kimi K31M
Grok 4.20 Reasoning1M
Grok 4.20 Non-Reasoning1M
Grok 4.20 Multi-Agent1M
Z.ai GLM 5.3 (on Mistral)1M
Qwen3.8 27B1M
Qwen3.8 Max Prime1M
Mistral Large 41M
Claude Fable 51M
Claude Mythos 51M
Claude Opus 51M
Claude Sonnet 51M
Claude Opus 4.81M
Claude Opus 4.71M
Claude Opus 4.61M
Claude Sonnet 4.61M
Grok 4.7500k
Grok 4.6500k
Grok 4.5500k
GPT-5.6 Cyber400k
Chat Latest400k
GPT-5400k
GPT-5 Mini400k
GPT-5 nano400k
GPT-5 Pro400k
GPT-5.2400k
GPT-5.2 Pro400k
GPT-5.4 Mini400k
GPT-5-Codex400k
GPT-5.1400k
GPT-5.1-Codex400k
GPT-5.1-Codex Mini400k
GPT-5.1-Codex-Max400k
GPT-5.2-Codex400k
GPT-5.3-Codex400k
GPT-5.4 nano400k
Grok Build 0.1256k
Mistral Medium 3.5256k
Mistral Small 4256k
Ministral 3 14B256k
Ministral 3 8B256k
Ministral 3 3B256k
Command A256k
Command A Reasoning256k
North Mini Code256k
Kimi K2.7 Code256k
Mistral Large 3256k
Kimi K2.6256k
Claude Opus 4.5200k
Claude Haiku 4.5200k
o3200k
o3-pro200k
Claude Sonnet 4.5200k
codex-mini-latest200k
o1200k
o1-pro200k
o3-deep-research200k
o3-mini200k
o4-mini200k
o4-mini-deep-research200k
gpt-oss-120b131k
gpt-oss-20b131k
Command A+128k
Codestral128k
Aya Expanse 32B128k
Command A Vision128k
Command R7B128k
Command R (08-2024)128k
Command R+ (08-2024)128k
ChatGPT-4o128k
GPT-4 Turbo128k
GPT-4 Turbo Preview128k
GPT-4.5 Preview128k
GPT-4o128k
GPT-4o Mini128k
GPT-4o Mini Search Preview128k
GPT-4o Search Preview128k
GPT-5 Chat128k
GPT-5.1 Chat128k
GPT-5.2 Chat128k
GPT-5.3 Chat128k
o1 Preview128k
o1-mini128k
Command R128k
Command R+128k
Voxtral Small32k
GPT-3.5 Turbo16k
babbage-00216k
davinci-00216k
Aya Vision 32B16k
computer-use-preview8k
GPT-48k
Tiny Aya Earth8k
Tiny Aya Global8k
Claude Mythos 5.11M

Alternatives

Same category, closest price, other providers first.

GPT-6 Astra OpenAI

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Chat Latest OpenAI

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More from Anthropic

Anthropic
# Model Input Output Context Released Capabilities Price change
1
Claude Fable 5.1 Anthropic
$10.00 $50.00 1M September 2026
2
Claude Opus 5.5 Anthropic
$4.00 $20.00 1M September 2026
3
Claude Sonnet 5.5 Anthropic
$2.00 $10.00 1M September 2026
4
Claude Haiku 5.5 Anthropic
$0.10 $0.50 1M October 2026
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Frequently asked questions

How much does Claude Mythos 5.1 cost?

Claude Mythos 5.1 is priced at cached input $0.25 / 1M tokens, cache write $12.50 / 1M tokens, input $10.00 / 1M tokens, output $50.00 / 1M tokens, according to Anthropic's published pricing (checked Oct 22, 2026).

What is the context window of Claude Mythos 5.1?

Claude Mythos 5.1 accepts up to 1M tokens per request. It can write up to 128k tokens in one response.

Is Claude Mythos 5.1 still available?

Yes. Claude Mythos 5.1 is generally available through the Anthropic API.

When was Claude Mythos 5.1 released?

Claude Mythos 5.1 was released in September 2026.

What is the API model ID for Claude Mythos 5.1?

Use claude-mythos-5-1 when calling the Anthropic API.

What are the alternatives to Claude Mythos 5.1?

Models in the same category at a similar price include GPT-6 Astra (OpenAI), GPT-6 Astra Pro (OpenAI), Claude Fable 5.1 (Anthropic) and Chat Latest (OpenAI).