Model Comparison

Claude Mythos Preview vs Claude Opus 4.8Which is better in 2026?

Claude Mythos Preview significantly outperforms across most benchmarks. Claude Opus 4.8 is 5.0x cheaper per token.

Verdict: Claude Mythos Preview vs Claude Opus 4.8 — which is better?

Claude Mythos Preview (by Anthropic) and Claude Opus 4.8 (by Anthropic) 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 11 benchmarks (BrowseComp, CharXiv-R, CyberGym, GPQA, Graphwalks BFS >128k, Humanity's Last Exam, SWE-bench Multilingual, SWE-Bench Multimodal, SWE-Bench Pro, SWE-Bench Verified, Terminal-Bench 2.0), while Claude Opus 4.8 is better at 1 benchmark (OSWorld-Verified). Claude Mythos Preview significantly outperforms across most benchmarks.

On price, Claude Opus 4.8 is roughly 5.0x 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 11 of 12 shared benchmarks

Choose Claude Opus 4.8 if…

  • cost matters — it's about 5.0x cheaper per token
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Performance Benchmarks

Comparative analysis across standard metrics

12 benchmarks

Claude Mythos Preview outperforms in 11 benchmarks (BrowseComp, CharXiv-R, CyberGym, GPQA, Graphwalks BFS >128k, Humanity's Last Exam, SWE-bench Multilingual, SWE-Bench Multimodal, SWE-Bench Pro, SWE-Bench Verified, Terminal-Bench 2.0), while Claude Opus 4.8 is better at 1 benchmark (OSWorld-Verified).

Claude Mythos Preview significantly outperforms across most benchmarks.

Thu Jun 11 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Claude Opus 4.8 costs less

For input processing, Claude Mythos Preview ($25.00/1M tokens) is 5.0x more expensive than Claude Opus 4.8 ($5.00/1M tokens).

For output processing, Claude Mythos Preview ($125.00/1M tokens) is 5.0x more expensive than Claude Opus 4.8 ($25.00/1M tokens).

In conclusion, Claude Mythos Preview is more expensive than Claude Opus 4.8.*

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

Lowest available price from all providers
Thu Jun 11 2026 • llm-stats.com
Anthropic
Claude Mythos Preview
Input tokens$25.00
Output tokens$125.00
Best providerAnthropic
Anthropic
Claude Opus 4.8
Input tokens$5.00
Output tokens$25.00
Best providerAnthropic
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Only Claude Opus 4.8 specifies input context (1,000,000 tokens). Only Claude Opus 4.8 specifies output context (128,000 tokens).

Anthropic
Claude Mythos Preview
Input- tokens
Output- tokens
Anthropic
Claude Opus 4.8
Input1,000,000 tokens
Output128,000 tokens
Thu Jun 11 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Claude Mythos Preview and Claude Opus 4.8 support multimodal inputs.

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

Claude Mythos Preview

Text
Images
Audio
Video

Claude Opus 4.8

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 Preview

Proprietary

Closed source

Claude Opus 4.8

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Opus 4.8 was released on 2026-05-28, while Claude Mythos Preview's release date is not specified.

We can confirm Claude Opus 4.8's release timeline, but cannot make a direct age comparison without Claude Mythos Preview's release date.

Claude Mythos Preview

—

Claude Opus 4.8

May 28, 2026

2 weeks 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. Claude Opus 4.8 is available from Anthropic, Vertex AI.

Claude Mythos Preview

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

Claude Opus 4.8

anthropic logo
Anthropic
Input Price:Input: $5.00/1MOutput Price:Output: $25.00/1M
vertex logo
Unknown Organization
Input Price:Input: $5.00/1MOutput Price:Output: $25.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Anthropic
Higher BrowseComp score (86.9% vs 84.3%)
Higher CharXiv-R score (93.2% vs 89.9%)
Higher CyberGym score (83.1% vs 78.8%)
Higher GPQA score (94.6% vs 93.6%)
Higher Graphwalks BFS >128k score (80.0% vs 68.1%)
Higher Humanity's Last Exam score (64.7% vs 57.9%)
Higher SWE-bench Multilingual score (87.3% vs 84.4%)
Higher SWE-Bench Multimodal score (59.0% vs 38.4%)
Higher SWE-Bench Pro score (77.8% vs 69.2%)
Higher SWE-Bench Verified score (93.9% vs 88.6%)
Higher Terminal-Bench 2.0 score (82.0% vs 74.6%)
Anthropic
Larger context window (1,000,000 tokens)
Less expensive input tokens
Less expensive output tokens
Higher OSWorld-Verified score (83.4% vs 79.6%)

Detailed Comparison

AI Model Comparison Table
Feature
Anthropic
Claude Mythos Preview
Anthropic
Claude Opus 4.8

FAQ

Common questions about Claude Mythos Preview vs Claude Opus 4.8.

Which is better, Claude Mythos Preview or Claude Opus 4.8?

Claude Mythos Preview significantly outperforms across most benchmarks. Claude Mythos Preview is made by Anthropic and Claude Opus 4.8 is made by Anthropic. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Claude Mythos Preview compare to Claude Opus 4.8 in benchmarks?

Claude Mythos Preview scores CyBench: 100.0%, USAMO25: 97.6%, GPQA: 94.6%, SWE-Bench Verified: 93.9%, CharXiv-R: 93.2%. Claude Opus 4.8 scores GPQA: 93.6%, DeepSearchQA: 93.1%, CharXiv-R: 89.9%, SWE-Bench Verified: 88.6%, ScreenSpot Pro: 87.9%.

Is Claude Mythos Preview cheaper than Claude Opus 4.8?

Claude Opus 4.8 is 5.0x cheaper for input tokens. Claude Mythos Preview costs $25.00/M input and $125.00/M output via anthropic. Claude Opus 4.8 costs $5.00/M input and $25.00/M output via anthropic.

What are the context window sizes for Claude Mythos Preview and Claude Opus 4.8?

Claude Mythos Preview supports an unknown number of tokens and Claude Opus 4.8 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 Claude Opus 4.8?

Key differences include input pricing ($25.00 vs $5.00/M). See the full comparison above for benchmark-by-benchmark results.

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