Claude Opus 4.8 is the stronger all-rounder.Claude 3.5 Sonnet is cheaper.
Scores updated · 8 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.
Claude 3.5 Sonnet costs 40% less for the same work.
The biggest differences
The tests each model wins by the widest margin, up to three each. Scores are out of 100.
Where Claude Opus 4.8 pulls ahead
- Very hard expert questions across many subjectsHumanity's Last Exam+45.5points ahead
- Fixes real GitHub issues in Python projectsSWE-bench Verified+39.6points ahead
- Common-sense trick questionsSimpleBench+37.3points ahead
Where Claude 3.5 Sonnet pulls ahead
No clear win on a test scored out of 100.
Every test, side by side
All 8 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingClaude Opus 4.8
- SWE-bench VerifiedClaude Opus 4.8 by 39.64988.6+39.6
- SciCodeClaude Opus 4.8 by 22.831.654.4+22.8
ReasoningClaude Opus 4.8
- Humanity's Last ExamClaude Opus 4.8 by 45.53.248.7+45.5
- SimpleBenchClaude Opus 4.8 by 37.327.564.8+37.3
- GPQA DiamondClaude Opus 4.8 by 365692+36
Other results3 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.
- Artificial Analysis Coding IndexClaude Opus 4.8 by 48.32674.3+48.3
- AA IntelligenceClaude Opus 4.8 by 34.67.241.8+34.6
- frontiermath_tier_4_v1Claude Opus 4.8 by 31.3031.3+31.3
Questions people ask
Which is better, Claude 3.5 Sonnet or Claude Opus 4.8?
Claude Opus 4.8 wins all two areas where both have results: coding and reasoning. Claude 3.5 Sonnet wins none, but costs 40% less.
Which is better for coding?
Claude Opus 4.8. It wins 2 of the 2 coding tests both models report; Claude 3.5 Sonnet wins none.
Which is cheaper?
Claude 3.5 Sonnet costs $3.00 per million input tokens and $15.00 per million output tokens; Claude Opus 4.8 costs $5.00 and $25.00. That makes Claude 3.5 Sonnet about 40% cheaper for the same work.
How do you compare the two?
We use the 8 benchmark tests both models have published scores on. The verdict counts the 5 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 3 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.