Claude Fable 5.1 is the stronger all-rounder.
Scores updated · 23 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.
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 Fable 5.1 pulls ahead
- Command-line tasks in a real terminalTerminal-Bench 2.1+3.4points ahead
- Fixes real GitHub issues in many programming languagesSWE-bench Multilingual+2.5points ahead
- Very hard expert questions across many subjectsHumanity's Last Exam+1.3points ahead
Where Claude Mythos 5 pulls ahead
No clear win on a test scored out of 100.
Every test, side by side
All 23 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingClaude Fable 5.1
- Terminal-Bench 2.1Claude Fable 5.1 by 3.491.488+3.4
- SWE-bench MultilingualClaude Fable 5.1 by 2.589.186.6+2.5
- SWE-bench ProClaude Fable 5.1 by 1.281.280+1.2
ReasoningClaude Fable 5.1
- Humanity's Last ExamClaude Fable 5.1 by 1.359.157.8+1.3
- CritPtClaude Fable 5.1 by 1.129.728.6+1.1
- ARC-AGI-2tie9089.2tie
Other results17 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.
- Terminal-Bench-Science 0.1Claude Fable 5.1 by 27.952.624.7+27.9
- Terminal-Bench 4.0Claude Fable 5.1 by 13.855.842+13.8
- GDPval-AA v2Claude Fable 5.1 by 130 rating points18531723+130 rating
- RiemannBenchClaude Fable 5.1 by 10.665.655+10.6
- OSWorld 2.0 (strict)Claude Fable 5.1 by 5.641.736.1+5.6
- OSWorld 2.0 (partial)Claude Fable 5.1 by 577.972.9+5
- HealthBench (raw)Claude Fable 5.1 by 4.266.762.5+4.2
- HealthBench Professional (raw)Claude Fable 5.1 by 3.974.270.3+3.9
- GDP (Surge AI)Claude Mythos 5 by 2.285.187.3+2.2
- OfficeQA ProClaude Fable 5.1 by 1.96967.1+1.9
- Toolathlon VerifiedClaude Mythos 5 by 1.577.879.3+1.5
- Program BenchClaude Fable 5.1 by 1.387.686.3+1.3
- HealthBench ProfessionalClaude Mythos 5 by 1.262.163.3+1.2
- HLE (with tools)Claude Fable 5.1 by 1.26563.8+1.2
- OfficeQAClaude Fable 5.1 by 1.280.279+1.2
- ARC-AGI-1Claude Mythos 5 by 197.598.5+1
- SWE-bench Multimodaltie54.754.1tie
Questions people ask
Which is better, Claude Fable 5.1 or Claude Mythos 5?
Claude Fable 5.1 wins all two areas where both have results: coding and reasoning. Claude Mythos 5 wins none.
Which is better for coding?
Claude Fable 5.1. It wins 3 of the 3 coding tests both models report; Claude Mythos 5 wins none.
Which is cheaper?
Claude Fable 5.1 costs $10.00 per million input tokens and $50.00 per million output tokens; Claude Mythos 5 costs $10.00 and $50.00. For a million tokens read plus a million written, they cost about the same.
How do you compare the two?
We use the 23 benchmark tests both models have published scores on. The verdict counts the 6 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 17 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.