Claude Mythos Preview vs Mercury 3
Claude Mythos Preview leads the LLM Stats Score 54.5 to 36.1. Mercury 3 is 307.7x cheaper per token.
Anthropic · Inception · Updated for 2026
Which is better?
Claude Mythos Preview leads the overall LLM Stats Score 54.5 to 36.1, ranking #5 overall.
In the 1 individual benchmarks reported for both models, Claude Mythos Preview wins 1; this is a narrower head-to-head signal than the composite indexes.
On price, Mercury 3 is roughly 307.7x 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 54.5 and ranks #5 on LLM Stats
- your work emphasizes reasoning and agents — it leads those capability indexes
- you value its reported benchmark strengths — it wins 1 of 1 exact shared results
Choose Mercury 3
- cost matters — it's about 307.7x cheaper per token
At a glance
The differences that matter most.
Individual benchmarks
16 reported for Claude Mythos Preview · 12 for Mercury 3
Claude Mythos Preview outperforms in 1 benchmarks (GPQA), while Mercury 3 is better at 0 benchmarks.
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 250.0x more expensive than Mercury 3 ($0.10/1M tokens).
For output processing, Claude Mythos Preview ($125.00/1M tokens) is 357.1x more expensive than Mercury 3 ($0.35/1M tokens).
In conclusion, Claude Mythos Preview is more expensive than Mercury 3.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Only Mercury 3 specifies input context (1,000,000 tokens). Only Mercury 3 specifies output context (131,072 tokens).
Input capabilities
Documented input modalities across available providers
Claude Mythos Preview supports multimodal inputs, whereas Mercury 3 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
Mercury 3
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
Mercury 3 was released on 2026-10-19, while Claude Mythos Preview's release date is not specified.
We can confirm Mercury 3's release timeline, but cannot make a direct age comparison without Claude Mythos Preview's release date.
—
Oct 19, 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.
Provider Availability
Claude Mythos Preview is available from Anthropic. Mercury 3 is available from Inception.
Claude Mythos Preview
Mercury 3
Outputs Comparison
Judge for yourself.
Run your own prompts against Claude Mythos Preview and Mercury 3 side-by-side, then vote on the output you prefer.
FAQ
Common questions about Claude Mythos Preview vs Mercury 3.