Claude Mythos 5.1 vs Solar Pro 4
Claude Mythos 5.1 leads the LLM Stats Score 45.3 to 35.2. Solar Pro 4 is 38.1x cheaper per token.
Anthropic · Upstage · Updated for 2026
Which is better?
Claude Mythos 5.1 leads the overall LLM Stats Score 45.3 to 35.2, ranking #33 overall.
On price, Solar Pro 4 is roughly 38.1x 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
- overall performance matters — it scores 45.3 and ranks #33 on LLM Stats
- your work emphasizes reasoning and coding — it leads those capability indexes
- 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 Solar Pro 4
- cost matters — it's about 38.1x cheaper per token
At a glance
The differences that matter most.
Individual benchmarks
1 reported for Claude Mythos 5.1 · 9 for Solar Pro 4
Claude Mythos 5.1 and Solar Pro 4don'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
For input processing, Claude Mythos 5.1 ($10.00/1M tokens) is 33.3x more expensive than Solar Pro 4 ($0.30/1M tokens).
For output processing, Claude Mythos 5.1 ($50.00/1M tokens) is 41.7x more expensive than Solar Pro 4 ($1.20/1M tokens).
In conclusion, Claude Mythos 5.1 is more expensive than Solar Pro 4.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Claude Mythos 5.1 accepts 1,000,000 input tokens compared to Solar Pro 4's 524,288 tokens. Solar Pro 4 can generate longer responses up to 131,072 tokens, while Claude Mythos 5.1 is limited to 128,000 tokens.
Input capabilities
Documented input modalities across available providers
Claude Mythos 5.1 supports multimodal inputs, whereas Solar Pro 4 does not.
Claude Mythos 5.1 can handle both text and other forms of data like images, making it suitable for multimodal applications.
Claude Mythos 5.1
Solar Pro 4
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 Mythos 5.1 was released on 2026-09-01, while Solar Pro 4 was released on 2026-08-06.
Claude Mythos 5.1 is 1 month newer than Solar Pro 4.
Sep 1, 2026
3 weeks ago
3w newerAug 6, 2026
1 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 5.1 is available from Anthropic. Solar Pro 4 is available from Upstage.
Claude Mythos 5.1
Solar Pro 4
Outputs Comparison
Judge for yourself.
Run your own prompts against Claude Mythos 5.1 and Solar Pro 4 side-by-side, then vote on the output you prefer.
FAQ
Common questions about Claude Mythos 5.1 vs Solar Pro 4.