Benchmark Almanac

SWE-EVO

Fading

Coding agents implement release-note changes in seven mature Python projects, editing about 21 files per task. Large test suites check each of the 48 tasks.

The paper reports GPT-5.4 with OpenHands at 25%. The arXiv record reached version 6.

Made by
Le, Thai et al.
Released
December 2025
Kind
Fixing real repositories
Level
Expert
Scored
Checked automatically
Answers
Agent task
Last in a launch post
February 2026, dropped before it saturated
Last model added
February 2026

In the authors’ words

Existing benchmarks for AI coding agents focus on isolated, single-issue tasks such as fixing a bug or adding a small feature. However, real-world software engineering is a long-horizon endeavor: developers interpret high-level requirements, coordinate changes across many files, and evolve codebases over multiple iterations while preserving functionality. We introduce SWE-EVO, a benchmark for this long-horizon software evolution challenge. Constructed from release notes of seven mature open-source Python projects, SWE-EVO comprises 48 tasks requiring multi-step modifications spanning an average of 21 files, validated against test suites averaging 874 tests per instance. Experiments reveal a striking capability gap: GPT-5.4 with OpenHands achieves only 25% on SWE-EVO versus 72.80% achieved by GPT-5.2 on SWE-Bench Verified, showing that current agents struggle with sustained, multi-file reasoning. We also propose Fix Rate, a metric capturing partial progress on these complex, long-horizon tasks.

Abstract of SWE-EVO: Benchmarking Coding Agents in Long-Horizon Software Evolution Scenarios (arXiv:2512.18470, CC0)
1
Model scored in lab cards
1
Launch post lists it, from 1 lab
1
System card reports it, from 1 lab

Seed2.0 Pro leads with 8.50%

Best score per model as labs report them in their own cards. Labs pick their own settings, so these compare less cleanly than independent runs.

  1. 1 Seed2.0 Pro 8.50%

Source: Labs’ model cards

#ModelScoreSettingDateSource
1 Seed2.0 Pro 8.50% Feb 2026 Lab model card

Scores over time

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

Reported by the lab in its model card
0% 20% 40% 60% 80% 100% 2026 Near the ceiling (85%) Seed2.0 Pro 0% 20% 40% 60% 80% 100% 2026 Near the ceiling (85%) Seed2.0 Pro

Source: Labs’ model cards

Labs headline it less often now, last in February 2026

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.

ByteDance Seed
DateLaunch postScoreAs the post writes it
Feb 14, 2026 Seed2.0 Pro 8.5 SWE-Evo

One system card reports it

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.

DateDocumentScoreAs the document writes itSection
Feb 14, 2026 Seed2.0 Pro model card 8.5 SWE-Evo (Table 11) Capabilities

More in Coding

All 282 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%
  • 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%
  • SWE-bench Multilingual In use 300 GitHub-issue tasks across nine programming languages in SWE-bench format. Patch graded by repository tests. Claude Fable 5.2 96.6%
  • 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