Head-to-head comparison across 1benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
Claude Haiku 4.5
59
Claude Sonnet 4.5
67
Pick Claude Sonnet 4.5 if you want the stronger benchmark profile. Claude Haiku 4.5 only becomes the better choice if you want the cheaper token bill.
Coding
+3.9 difference
Claude Haiku 4.5
Claude Sonnet 4.5
$1 / $5
$3 / $15
N/A
N/A
N/A
N/A
200K
200K
Pick Claude Sonnet 4.5 if you want the stronger benchmark profile. Claude Haiku 4.5 only becomes the better choice if you want the cheaper token bill.
Claude Sonnet 4.5 is clearly ahead on the provisional aggregate, 67 to 59. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Claude Sonnet 4.5's sharpest advantage is in coding, where it averages 77.2 against 73.3. The single biggest benchmark swing on the page is SWE-bench Verified, 73.3% to 77.2%.
Claude Sonnet 4.5 is also the more expensive model on tokens at $3.00 input / $15.00 output per 1M tokens, versus $1.00 input / $5.00 output per 1M tokens for Claude Haiku 4.5. That is roughly 3.0x on output cost alone.
Claude Sonnet 4.5 is ahead on BenchLM's provisional leaderboard, 67 to 59. The biggest single separator in this matchup is SWE-bench Verified, where the scores are 73.3% and 77.2%.
Claude Sonnet 4.5 has the edge for coding in this comparison, averaging 77.2 versus 73.3. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.
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