Benchmark Almanac

Senior SWE-Bench

Claude Opus 5.5 39.3% leads since Sep 2026 Not in model cards

Agents build features and fix runtime bugs in real open-source repos from loose, natural instructions. Behavioral tests and codebase quality metrics give a tasteful solve rate.

100 tasks, 50 public. The leaderboard lists 23 models, led by Claude Opus 5.5 at 39.3% tasteful solves. Launched 2026-06-30.

Made by Snorkel AI Released Jun 2026 Fixing real repositories Public tasks plus a private test set Last model added Sep 2026 Scores refreshed 2 Nov 2026
Level
Expert Specialists with years of training, often over hours of work
Scored
Checked automatically A program checks the result against an answer key, unit tests or the expected final state.
Answers
Agent task Many steps in a terminal, browser, desktop, app, game or robot.
snorkel-ai/senior-swe-bench-v2026.06 57 stars Dataset Leaderboard senior-swe-bench.snorkel.ai
23
Models scored on its own leaderboard

Claude Opus 5.5 leads with 39.3%

Best score per model from the benchmark's own leaderboard, read on 2 Nov 2026. Where a model ran with several settings or harnesses, we keep its best.

23 models. Scroll sideways for the rest.

  1. 39.3 Claude Opus 5.5
  2. 36.8 GPT-6 Astra
  3. 34.7 Claude Fable 5
  4. 34.7 GPT-5.6 Sol
  5. 34.7 Claude Opus 5
  6. 34.7 Claude Fable 5.1
  7. 30.5 Claude Opus 4.8
  8. 29.5 GPT-5.5
  9. 28.0 Claude Sonnet 5
  10. 27.7 Gemini 4 Argon
  11. 27.4 GPT-5.6 Terra
  12. 27.4 Grok 4.7
  13. 26.3 Grok 4.6
  14. 23.2 Grok 4.5
  15. 22.7 DeepSeek V4.1 Flash
  16. 21.1 MiniMax-M3
  17. 20.2 Kimi K3
  18. 18.1 Claude Opus 4.7
  19. 17.9 GLM-5.2
  20. 16.8 GPT-5.4
  21. 14.7 Gemini 3.7 Flash
  22. 6.32 Gemini 3.5 Flash
  23. 2.11 Gemini 3.1 Pro
  1. 1 Claude Opus 5.5 high 39.3%
  2. 2 GPT-6 Astra high 36.8%
  3. 3 Claude Fable 5 high 34.7%
  4. 4 GPT-5.6 Sol xhigh 34.7%
  5. 5 Claude Opus 5 high 34.7%
  6. 6 Claude Fable 5.1 medium 34.7%
  7. 7 Claude Opus 4.8 max 30.5%
  8. 8 GPT-5.5 xhigh 29.5%
  9. 9 Claude Sonnet 5 max 28%
  10. 10 Gemini 4 Argon medium 27.7%
  11. 11 GPT-5.6 Terra high 27.4%
  12. 12 Grok 4.7 xhigh 27.4%
  13. 13 Grok 4.6 high 26.3%
  14. 14 Grok 4.5 medium 23.2%
  15. 15 DeepSeek V4.1 Flash high 22.7%
  16. 16 MiniMax-M3 adaptive 21.1%
  17. 17 Kimi K3 max 20.2%
  18. 18 Claude Opus 4.7 max 18.1%
  19. 19 GLM-5.2 max 17.9%
  20. 20 GPT-5.4 xhigh 16.8%
  21. 21 Gemini 3.7 Flash high 14.7%
  22. 22 Gemini 3.5 Flash high 6.32%
  23. 23 Gemini 3.1 Pro high 2.11%
#ModelScoreSettingDateSource
1 Claude Opus 5.5 39.3% high, mini-swe-agent Sep 2026 Official leaderboard
2 GPT-6 Astra 36.8% high, mini-swe-agent Sep 2026 Official leaderboard
3 Claude Fable 5 34.7% high, mini-swe-agent Jun 2026 Official leaderboard
4 GPT-5.6 Sol 34.7% xhigh, mini-swe-agent Jul 2026 Official leaderboard
5 Claude Opus 5 34.7% high, mini-swe-agent Jul 2026 Official leaderboard
6 Claude Fable 5.1 34.7% medium, mini-swe-agent Sep 2026 Official leaderboard
7 Claude Opus 4.8 30.5% max, mini-swe-agent May 2026 Official leaderboard
8 GPT-5.5 29.5% xhigh, mini-swe-agent Apr 2026 Official leaderboard
9 Claude Sonnet 5 28% max, mini-swe-agent Jun 2026 Official leaderboard
10 Gemini 4 Argon 27.7% medium, mini-swe-agent Sep 2026 Official leaderboard
11 GPT-5.6 Terra 27.4% high, mini-swe-agent Jul 2026 Official leaderboard
12 Grok 4.7 27.4% xhigh, mini-swe-agent Sep 2026 Official leaderboard
13 Grok 4.6 26.3% high, mini-swe-agent Aug 2026 Official leaderboard
14 Grok 4.5 23.2% medium, mini-swe-agent Jul 2026 Official leaderboard
15 DeepSeek V4.1 Flash 22.7% high, mini-swe-agent Sep 2026 Official leaderboard
16 MiniMax-M3 21.1% adaptive, mini-swe-agent Jun 2026 Official leaderboard
17 Kimi K3 20.2% max, mini-swe-agent Jul 2026 Official leaderboard
18 Claude Opus 4.7 18.1% max, mini-swe-agent Apr 2026 Official leaderboard
19 GLM-5.2 17.9% max, mini-swe-agent Jun 2026 Official leaderboard
20 GPT-5.4 16.8% xhigh, mini-swe-agent Mar 2026 Official leaderboard
21 Gemini 3.7 Flash 14.7% high, mini-swe-agent Aug 2026 Official leaderboard
22 Gemini 3.5 Flash 6.32% high, mini-swe-agent May 2026 Official leaderboard
23 Gemini 3.1 Pro 2.11% high, mini-swe-agent Feb 2026 Official leaderboard

4 models have held number one since its release in Jun 2026

Lab claims count from the day the card came out, independent runs from the model’s release.

Anthropic OpenAI
Own leaderboard 4 leaders
Claude Opus 5.5 39.3%

Scores over time

All the scores we have, one dot each, so a model tested at several settings appears more than once.

On the benchmark’s own leaderboard Best so far
0% 20% 40% 60% 80% 100% 2026 Near the ceiling (85%) Claude Opus 5.5 Claude Fable 5 Claude Opus 4.8 Claude Opus 4.7 Gemini 3.1 Pro 0% 20% 40% 60% 80% 100% 2026 Near the ceiling (85%) Claude Opus 5.5 Claude Opus 4.8

No lab model card reports it yet

We read the headline results of 479 launch posts from 51 labs, and none of them list this benchmark.

More in Coding

All 243 in Coding
  • SWE-bench Verified In use 500 human-validated GitHub issues from 12 Python repos. Agent writes a patch that must pass hidden tests. Claude Opus 4.7 83.5%
  • SWE-bench Multilingual In use 300 GitHub-issue tasks across nine programming languages in SWE-bench format. Patch graded by repository tests. Claude Opus 5.5 93.9%
  • LiveCodeBench v6 In use Competitive programming problems collected after model cutoffs from LeetCode, AtCoder, Codeforces. Scored pass@1 on hidden tests. DeepSeek-V4-Pro 93.5%
  • DeepSWE In use 113 original long-horizon engineering tasks across 91 repos and five languages, written from scratch. Hand-written verifiers accept alternative solutions. GPT-6 Astra 74.1%
  • SciCode In use Scientist-curated research coding problems split into subproblems across natural sciences. Code checked against test cases. Seed2.1 Pro 59.8%
  • Codeforces rating In use Model solves recent Codeforces contest problems. An Elo-style rating is computed from simulated contest performance. DeepSeek V4.1 Flash 3,471