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Claude Mythos 5.1 vs GPT-5.2 Pro

Claude Mythos 5.1 and GPT-5.2 Pro are closely matched at 45.1 and 43.0 on the LLM Stats Score. Claude Mythos 5.1 is 2.9x cheaper per token.

Anthropic · OpenAI · Updated for 2026

Which is better?

Claude Mythos 5.1 and GPT-5.2 Pro are closely matched on the overall LLM Stats Score at 45.1 and 43.0.

On price, Claude Mythos 5.1 is roughly 2.9x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Claude Mythos 5.1 also accepts a larger context window (1,000,000 input tokens), making it the stronger choice for long documents and large codebases.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Claude Mythos 5.1

  • your work emphasizes agents — it leads those capability indexes
  • cost matters — it's about 2.9x cheaper per token
  • you process long inputs — it offers a 1,000,000 token context window
  • you want the most recent training data — it shipped Sep 2026

Choose GPT-5.2 Pro

  • you want predictable pricing at $21.00/M input and $168.00/M output

At a glance

The differences that matter most.

Claude Mythos 5.1
Anthropic
GPT-5.2 Pro
OpenAI
Core performance indexes
LLM Stats Score
45.1
#31
43.0
#43
Reasoning
44.4
#34
41.5
#46
Agents
34.5
#21
18.1
#69
Cost, coverage & limits
Benchmark wins
—
—
Input price
$10.00 / M
$21.00 / M
Output price
$50.00 / M
$168.00 / M
Context window
1,000,000
400,000

Individual benchmarks

1 reported for Claude Mythos 5.1 · 7 for GPT-5.2 Pro

No common benchmarks found

Claude Mythos 5.1 and GPT-5.2 Prodon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

Claude Mythos 5.1 costs less

For input processing, Claude Mythos 5.1 ($10.00/1M tokens) is 2.1x cheaper than GPT-5.2 Pro ($21.00/1M tokens).

For output processing, Claude Mythos 5.1 ($50.00/1M tokens) is 3.4x cheaper than GPT-5.2 Pro ($168.00/1M tokens).

In conclusion, GPT-5.2 Pro is more expensive than Claude Mythos 5.1.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Thu Sep 10 2026 • llm-stats.com
Anthropic
Claude Mythos 5.1
Input tokens$10.00
Output tokens$50.00
Best providerAnthropic
OpenAI
GPT-5.2 Pro
Input tokens$21.00
Output tokens$168.00
Best providerOpenAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Claude Mythos 5.1 accepts 1,000,000 input tokens compared to GPT-5.2 Pro's 400,000 tokens. Both models can generate responses up to 128,000 tokens.

Anthropic
Claude Mythos 5.1
Input1,000,000 tokens
Output128,000 tokens
OpenAI
GPT-5.2 Pro
Input400,000 tokens
Output128,000 tokens
Thu Sep 10 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude Mythos 5.1 and GPT-5.2 Pro support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Claude Mythos 5.1

Text
Images
Audio
Video

GPT-5.2 Pro

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Claude Mythos 5.1

Proprietary

Closed source

GPT-5.2 Pro

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Mythos 5.1 was released on 2026-09-01, while GPT-5.2 Pro was released on 2025-12-11.

Claude Mythos 5.1 is 9 months newer than GPT-5.2 Pro.

Claude Mythos 5.1

Sep 1, 2026

1 weeks ago

8mo newer
GPT-5.2 Pro

Dec 11, 2025

9 months ago

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Provider Availability

Claude Mythos 5.1 is available from Anthropic. GPT-5.2 Pro is available from OpenAI.

Claude Mythos 5.1

anthropic logo
Anthropic
Input Price:Input: $10.00/1MOutput Price:Output: $50.00/1M

GPT-5.2 Pro

openai logo
OpenAI
Input Price:Input: $21.00/1MOutput Price:Output: $168.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Claude Mythos 5.1 and GPT-5.2 Pro side-by-side, then vote on the output you prefer.

Claude Mythos 5.1
✓ Preferred
GPT-5.2 Pro
Open in Playground

FAQ

Common questions about Claude Mythos 5.1 vs GPT-5.2 Pro.

Which is better, Claude Mythos 5.1 or GPT-5.2 Pro?

Claude Mythos 5.1 and GPT-5.2 Pro are closely matched on the LLM Stats Score at 45.1 and 43.0. Claude Mythos 5.1 is made by Anthropic and GPT-5.2 Pro is made by OpenAI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Claude Mythos 5.1 compare to GPT-5.2 Pro in benchmarks?

Claude Mythos 5.1 scores Terminal-Bench 4.0: 60.9%. GPT-5.2 Pro scores AIME 2025: 100.0%, HMMT 2025: 100.0%, GPQA: 93.2%, ARC-AGI: 90.5%, BrowseComp: 77.9%.

Is Claude Mythos 5.1 cheaper than GPT-5.2 Pro?

Claude Mythos 5.1 is 2.1x cheaper for input tokens. Claude Mythos 5.1 costs $10.00/M input and $50.00/M output via anthropic. GPT-5.2 Pro costs $21.00/M input and $168.00/M output via openai.

What are the context window sizes for Claude Mythos 5.1 and GPT-5.2 Pro?

Claude Mythos 5.1 supports 1.0M tokens and GPT-5.2 Pro supports 400K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Mythos 5.1 and GPT-5.2 Pro?

Key differences include LLM Stats Score (45.1 vs 43.0), context window (1.0M vs 400K), input pricing ($10.00 vs $21.00/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Mythos 5.1 and GPT-5.2 Pro?

Claude Mythos 5.1 is developed by Anthropic and GPT-5.2 Pro is developed by OpenAI.

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