FrontierCode 1.1
Real-repo coding tasks graded for mergeability: correctness, regressions, lint, tests, scope and code quality. Failing any blocker scores zero.
Re-graded the 1.0 tasks: runs flagged for unfair internet use score zero, and over-strict checks were relaxed.
- 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
- Code A program or patch run against tests.
Claude Fable 5 leads with 53.5% among models released by Jun 2026
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. Every run is in the next chart.
The newest model with a score here came out in Jun 2026, and nobody has tested a newer one. Among the 20 highest-ranked models on the capability index, these have no score yet:
- GPT-6 Astra
- Claude Opus 5.5
- GPT-6.1 Terra
- GPT-6.1 Sol
- and 13 more
- 1 Claude Fable 5 xhigh 53.5%
- 2 Claude Opus 4.8 max 46.5%
- 3 GPT-5.5 xhigh 43%
- 4 Claude Sonnet 5 xhigh 42.7%
- 5 Claude Opus 4.7 max 38.5%
- 6 GPT-5.4 Mini xhigh 27%
- 7 Claude Opus 4.6 max 26.9%
- 8 Claude Sonnet 4.6 max 24.3%
| # | Model | Score | Setting | Date | Source |
|---|---|---|---|---|---|
| 1 | Claude Fable 5 | 53.5% | xhigh, Claude Code | Jun 2026 | Official leaderboard |
| 2 | Claude Opus 4.8 | 46.5% | max, Claude Code | May 2026 | Official leaderboard |
| 3 | GPT-5.5 | 43% | xhigh, Codex | Apr 2026 | Official leaderboard |
| 4 | Claude Sonnet 5 | 42.7% | xhigh, Claude Code | Jun 2026 | Official leaderboard |
| 5 | Claude Opus 4.7 | 38.5% | max, Claude Code | Apr 2026 | Official leaderboard |
| 6 | GPT-5.4 Mini | 27% | xhigh, Codex | Mar 2026 | Official leaderboard |
| 7 | Claude Opus 4.6 | 26.9% | max, Claude Code | Feb 2026 | Official leaderboard |
| 8 | Claude Sonnet 4.6 | 24.3% | max, Claude Code | Feb 2026 | Official leaderboard |
Labs report scores for 12 models in their cards. We plot every source in the charts below.
The best score, 53.5%, costs $13 a task
Runs on the cost frontier score higher than any run that's cheaper. The costs are the leaderboard's own estimates, so compare them only within this benchmark.
| Model | Effort | Harness | Score | Cost per task | Output tokens |
|---|---|---|---|---|---|
| Claude Fable 5 | xhigh | Claude Code | 53.5% | $13 | 58,558 |
| Claude Fable 5 | high | Claude Code | 52.7% | $9.48 | 43,483 |
| Claude Fable 5 | max | Claude Code | 51.6% | $19 | 80,761 |
| Claude Fable 5 | medium | Claude Code | 49.8% | $7.15 | 33,230 |
| Claude Fable 5 | low | Claude Code | 48% | $4.92 | 23,610 |
| Claude Opus 4.8 | max | Claude Code | 46.5% | $9.62 | 95,940 |
| Claude Opus 4.8 | xhigh | Claude Code | 45.5% | $6.78 | 65,742 |
| GPT-5.5 | xhigh | Codex | 43% | $4.04 | 24,992 |
| Claude Sonnet 5 | xhigh | Claude Code | 42.7% | $9.06 | 87,937 |
| Claude Sonnet 5 | max | Claude Code | 42.4% | $15 | 142,621 |
| Claude Opus 4.8 | high | Claude Code | 41% | $4.28 | 41,326 |
| GPT-5.5 | high | Codex | 40.6% | $3.12 | 18,422 |
| Claude Opus 4.8 | medium | Claude Code | 40.5% | $3.70 | 34,907 |
| Claude Sonnet 5 | high | Claude Code | 39.4% | $5.49 | 57,710 |
| Claude Opus 4.7 | max | Claude Code | 38.5% | $9.09 | 49,114 |
| GPT-5.5 | medium | Codex | 36.6% | $2.35 | 13,677 |
| Claude Sonnet 5 | medium | Claude Code | 35.2% | $3.43 | 38,269 |
| Claude Opus 4.7 | high | Claude Code | 35.2% | $5.03 | 30,140 |
| Claude Opus 4.8 | low | Claude Code | 35.1% | $2.68 | 25,194 |
| Claude Opus 4.7 | xhigh | Claude Code | 34.9% | $6.87 | 38,419 |
| GPT-5.5 | low | Codex | 30.6% | $1.65 | 8,855 |
| Claude Opus 4.7 | medium | Claude Code | 28.9% | $3.22 | 21,881 |
| Claude Sonnet 5 | low | Claude Code | 28.7% | $2.15 | 24,817 |
| Claude Opus 4.7 | low | Claude Code | 27.6% | $2.47 | 17,853 |
| GPT-5.4 Mini | xhigh | Codex | 27% | $1.52 | 90,933 |
| Claude Opus 4.6 | max | Claude Code | 26.9% | $3.73 | 28,870 |
| Claude Opus 4.6 | high | Claude Code | 26.6% | $3.98 | 26,677 |
| Claude Sonnet 4.6 | max | Claude Code | 24.3% | $2.90 | 44,192 |
| Claude Opus 4.6 | medium | Claude Code | 23.7% | $2.79 | 19,837 |
| Claude Sonnet 4.6 | high | Claude Code | 23.5% | $2.70 | 41,109 |
| GPT-5.4 Mini | high | Codex | 23.1% | $0.95 | 46,439 |
| Claude Sonnet 4.6 | medium | Claude Code | 21.1% | $2.30 | 33,357 |
| GPT-5.4 Mini | medium | Codex | 20.8% | $0.78 | 34,721 |
| Claude Opus 4.6 | low | Claude Code | 18.3% | $2.10 | 14,888 |
| Claude Sonnet 4.6 | low | Claude Code | 15% | $1.65 | 21,708 |
| GPT-5.4 Mini | low | Codex | 9.25% | $0.36 | 12,066 |
Number one over time
Lab claims count from the day the card came out, independent runs from the model’s release. We draw one row each for the benchmark’s own leaderboard and what labs claim in their cards.
Scores over time
All the scores we have, one dot each, so a model tested at several settings appears more than once.
5 labs put it in a launch post in the last six months
Launch posts from every lab that has listed it, one tick per post. Tall colored ticks include it, and short gray ones leave it out.
| Date | Launch post | Score | As the post writes it |
|---|---|---|---|
| 7 Oct 2026 | Claude Haiku 5.5 | 46.4 | Agentic coding FrontierCode 1.1 (Main) (max) |
| 28 Sep 2026 | Claude Sonnet 5.5 | 52.1 | Agentic coding FrontierCode 1.1 (Main) (Xhigh) |
| 22 Sep 2026 | GPT-6 Luna | 42.4 | FrontierCode (GPT-6 Luna max) |
| 22 Sep 2026 | GPT-6 Sol | 49.3 | FrontierCode 1.1 Main (GPT-6 Sol max) |
| 10 Sep 2026 | SWE-2 | 50 | FrontierCode 1.1 Main |
| 3 Sep 2026 | GPT-6 Astra | 64.5 | FrontierCode 1.1 Extended (score) |
| 13 Aug 2026 |  Gemini 3.7 Flash | 43.6 | FrontierCode 1.1 Main (Score) |
| 12 Aug 2026 | Grok 4.6 | 61.3 | FrontierCode v1.1 (Extended) |
| 8 Jul 2026 | SWE-1.7 | 42.3 | FrontierCode 1.1 Main |
7 system cards report it, from 3 labs
Besides launch posts, we read the system cards, model cards and technical reports labs publish with a release. They report far more, including safety and frontier-risk tests.
| Date | Document | Score | As the document writes it | Section |
|---|---|---|---|---|
| 7 Oct 2026 | Claude Haiku 5.5 system card | 46.4 | FrontierCode 1.1 (Main), max effort (xhigh 45.8, Extended 58.4 at max) (Table 8.1.A) | Capabilities |
| 28 Sep 2026 | Claude Sonnet 5.5 system card | 46.2 | FrontierCode v1.1 (Main) at max effort (xhigh 52.1%, Extended 59.1% max and 64.4% xhigh) (Table 8.1.A, 8.4) | Capabilities |
| 22 Sep 2026 | Claude Opus 5.5 system card | 54.4 | FrontierCode v1.1 (Main) at max effort (best 54.6% at medium. Extended 63.6% at max and 65.3% at medium), mean@5, run by Cognition (Table 8.1.A, 8.4) | Capabilities |
| 1 Sep 2026 | Claude Fable 5.1 system card | 50.9 | FrontierCode 1.1 (Main) overall score at medium effort, Fable 5.1's best effort level; FrontierCode 1.1 Extended 63.6% at medium (8.4) | Capabilities |
| 13 Aug 2026 | Gemini 3.7 Flash model card | 43.6 | FrontierCode 1.1 Main, score (results table, p.5) | Capabilities |
| 12 Aug 2026 | Grok 4.6 model card | 61.3 | FrontierCode v1.1, extended set of 150 samples, extended score, high, run by Cognition (2.3) | Capabilities |
| 24 Jul 2026 | Claude Opus 5 system card | 53.4 | FrontierCode 1.1 (Main) at its best effort level (medium), mean@5, run by Cognition (Extended 63.6% at medium) (Table 8.1.A, 8.4) | Capabilities |
Versions
We switch the top row to each new version when it comes out. Open it for one row per version. An old version stays in play while people still test it, so whoever first takes it past 85% gets credit for closing it out.
More 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