Model Comparison

Claude Mythos Preview vs DeepSeek-V4-Flash-0731Which is better in 2026?

Claude Mythos Preview significantly outperforms across most benchmarks. DeepSeek-V4-Flash-0731 is 444.4x cheaper per token.

Verdict: Claude Mythos Preview vs DeepSeek-V4-Flash-0731 — which is better?

Claude Mythos Preview (by Anthropic) and DeepSeek-V4-Flash-0731 (by DeepSeek) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

Claude Mythos Preview outperforms in 1 benchmarks (CyberGym), while DeepSeek-V4-Flash-0731 is better at 0 benchmarks. Claude Mythos Preview significantly outperforms across most benchmarks.

On price, DeepSeek-V4-Flash-0731 is roughly 444.4x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Choose Claude Mythos Preview if…

  • you want the strongest raw capability — it leads on 1 of 1 shared benchmarks

Choose DeepSeek-V4-Flash-0731 if…

  • cost matters — it's about 444.4x cheaper per token
  • you need open weights you can self-host or fine-tune

Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

Claude Mythos Preview outperforms in 1 benchmarks (CyberGym), while DeepSeek-V4-Flash-0731 is better at 0 benchmarks.

Claude Mythos Preview significantly outperforms across most benchmarks.

Tue Aug 04 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

DeepSeek-V4-Flash-0731 costs less

For input processing, Claude Mythos Preview ($25.00/1M tokens) is 277.8x more expensive than DeepSeek-V4-Flash-0731 ($0.09/1M tokens).

For output processing, Claude Mythos Preview ($125.00/1M tokens) is 694.4x more expensive than DeepSeek-V4-Flash-0731 ($0.18/1M tokens).

In conclusion, Claude Mythos Preview is more expensive than DeepSeek-V4-Flash-0731.*

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

Lowest available price from all providers
Tue Aug 04 2026 • llm-stats.com
Anthropic
Claude Mythos Preview
Input tokens$25.00
Output tokens$125.00
Best providerAnthropic
DeepSeek
DeepSeek-V4-Flash-0731
Input tokens$0.09
Output tokens$0.18
Best providerDeepinfra
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Only DeepSeek-V4-Flash-0731 specifies input context (1,048,576 tokens). Only DeepSeek-V4-Flash-0731 specifies output context (65,536 tokens).

Anthropic
Claude Mythos Preview
Input- tokens
Output- tokens
DeepSeek
DeepSeek-V4-Flash-0731
Input1,048,576 tokens
Output65,536 tokens
Tue Aug 04 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Claude Mythos Preview supports multimodal inputs, whereas DeepSeek-V4-Flash-0731 does not.

Claude Mythos Preview can handle both text and other forms of data like images, making it suitable for multimodal applications.

Claude Mythos Preview

Text
Images
Audio
Video

DeepSeek-V4-Flash-0731

Text
Images
Audio
Video

License

Usage and distribution terms

Claude Mythos Preview is licensed under a proprietary license, while DeepSeek-V4-Flash-0731 uses MIT.

License differences may affect how you can use these models in commercial or open-source projects.

Claude Mythos Preview

Proprietary

Closed source

DeepSeek-V4-Flash-0731

MIT

Open weights

Release Timeline

When each model was launched

DeepSeek-V4-Flash-0731 was released on 2026-07-31, while Claude Mythos Preview's release date is not specified.

We can confirm DeepSeek-V4-Flash-0731's release timeline, but cannot make a direct age comparison without Claude Mythos Preview's release date.

Claude Mythos Preview

—

DeepSeek-V4-Flash-0731

Jul 31, 2026

3 days 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 Preview is available from Anthropic. DeepSeek-V4-Flash-0731 is available from DeepInfra, Fireworks, Novita.

Claude Mythos Preview

anthropic logo
Anthropic
Input Price:Input: $25.00/1MOutput Price:Output: $125.00/1M

DeepSeek-V4-Flash-0731

deepinfra logo
Deepinfra
Input Price:Input: $0.09/1MOutput Price:Output: $0.18/1M
fireworks logo
Fireworks
Input Price:Input: $0.14/1MOutput Price:Output: $0.28/1M
novita logo
Novita
Input Price:Input: $0.14/1MOutput Price:Output: $0.28/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Anthropic
Supports multimodal inputs
Higher CyberGym score (83.1% vs 76.7%)
DeepSeek
Larger context window (1,048,576 tokens)
Less expensive input tokens
Less expensive output tokens
Has open weights

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Claude Mythos Preview and DeepSeek-V4-Flash-0731 side-by-side, then vote on the output you prefer.

Claude Mythos Preview
✓ Preferred
DeepSeek-V4-Flash-0731
Open in Playground
AI Model Comparison Table
Feature
Anthropic
Claude Mythos Preview
DeepSeek
DeepSeek-V4-Flash-0731

FAQ

Common questions about Claude Mythos Preview vs DeepSeek-V4-Flash-0731.

Which is better, Claude Mythos Preview or DeepSeek-V4-Flash-0731?

Claude Mythos Preview significantly outperforms across most benchmarks. Claude Mythos Preview is made by Anthropic and DeepSeek-V4-Flash-0731 is made by DeepSeek. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Claude Mythos Preview compare to DeepSeek-V4-Flash-0731 in benchmarks?

Claude Mythos Preview scores CyBench: 100.0%, USAMO25: 97.6%, GPQA: 94.6%, SWE-Bench Verified: 93.9%, CharXiv-R: 93.2%. DeepSeek-V4-Flash-0731 scores Terminal-Bench 2.1: 82.7%, CyberGym: 76.7%, Toolathlon: 70.3%, DSBench-FullStack: 68.7%, DSBench-Hard: 59.6%.

Is Claude Mythos Preview cheaper than DeepSeek-V4-Flash-0731?

DeepSeek-V4-Flash-0731 is 277.8x cheaper for input tokens. Claude Mythos Preview costs $25.00/M input and $125.00/M output via anthropic. DeepSeek-V4-Flash-0731 costs $0.09/M input and $0.18/M output via deepinfra.

What are the context window sizes for Claude Mythos Preview and DeepSeek-V4-Flash-0731?

Claude Mythos Preview supports an unknown number of tokens and DeepSeek-V4-Flash-0731 supports 1.0M 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 Preview and DeepSeek-V4-Flash-0731?

Key differences include input pricing ($25.00 vs $0.09/M), multimodal support (yes vs no), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Mythos Preview and DeepSeek-V4-Flash-0731?

Claude Mythos Preview is developed by Anthropic and DeepSeek-V4-Flash-0731 is developed by DeepSeek.

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