Claude Mythos Preview vs Claude Opus 4.8
Claude Mythos Preview leads the LLM Stats Score 54.4 to 49.8. Claude Opus 4.8 is 5.0x cheaper per token.
Anthropic · Anthropic · Updated for 2026
Which is better?
Claude Mythos Preview leads the overall LLM Stats Score 54.4 to 49.8, ranking #5 overall.
In the 12 individual benchmarks reported for both models, Claude Mythos Preview wins 11; this is a narrower head-to-head signal than the composite indexes.
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.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose Claude Mythos Preview
- overall performance matters — it scores 54.4 and ranks #5 on LLM Stats
- your work emphasizes reasoning — it leads those capability indexes
- you value its reported benchmark strengths — it wins 11 of 12 exact shared results
Choose Claude Opus 4.8
- cost matters — it's about 5.0x cheaper per token
At a glance
The differences that matter most.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
16 reported for Claude Mythos Preview · 27 for Claude Opus 4.8
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.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
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
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).
Input capabilities
Documented input modalities across available providers
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
Claude Opus 4.8
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
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.
—
May 28, 2026
4 months ago
Knowledge Cutoff
When training data ends
Neither model specifies a knowledge cutoff date.
Unable to compare the recency of their training data.
Provider Availability
Claude Mythos Preview is available from Anthropic. Claude Opus 4.8 is available from Anthropic, DeepInfra, Vertex AI.
Claude Mythos Preview
Claude Opus 4.8
Outputs Comparison
Judge for yourself.
Run your own prompts against Claude Mythos Preview and Claude Opus 4.8 side-by-side, then vote on the output you prefer.
FAQ
Common questions about Claude Mythos Preview vs Claude Opus 4.8.