Claude Mythos 5 wins more areas, narrowly.
Scores updated · 7 tests both models report · How we compare
Where each one wins
Tests won in each of the two areas where both have results. Each piece is one test, so a longer bar means more evidence; grey means the two scored within a point of each other.
Reasoning rests on a single test.
What it costs
Prices per million tokens, roughly 750,000 words. The bars show the cost of a million tokens read plus a million written.
The biggest differences
The tests each model wins by the widest margin, up to three each. Scores are out of 100.
Where Claude Mythos 5 pulls ahead
- Long, multi-file coding tasks in real codebasesSWE-bench Pro+15.2points ahead
- Fixes real GitHub issues in many programming languagesSWE-bench Multilingual+2.9points ahead
Where Haiku 5.5 pulls ahead
No clear win on a test scored out of 100.
Every test, side by side
All 7 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingClaude Mythos 5
- SWE-bench ProClaude Mythos 5 by 15.28064.8+15.2
- SWE-bench MultilingualClaude Mythos 5 by 2.986.683.7+2.9
Other results4 tests, not counted
Tests outside the eight areas. They are not counted above: several are summary scores built from other tests, or the same test under another name.
- SWE-bench MultimodalClaude Mythos 5 by 23.454.130.7+23.4
- Program BenchClaude Mythos 5 by 4.386.382+4.3
- Terminal-Bench-Science 0.1Claude Mythos 5 by 4.124.720.6+4.1
- Terminal-Bench 4.0Claude Mythos 5 by 2.84239.2+2.8
Questions people ask
Which is better, Claude Mythos 5 or Haiku 5.5?
Claude Mythos 5 wins one of the two areas where both have results: coding. Haiku 5.5 wins none. They are level on reasoning.
Which is better for coding?
Claude Mythos 5. It wins 2 of the 2 coding tests both models report; Haiku 5.5 wins none.
How do you compare the two?
We use the 7 benchmark tests both models have published scores on. The verdict counts the 3 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 4 are listed but not counted, because several are summary scores or repeat a test. Each score is the one shown on the model's own page.