Benchmark Almanac

SWE-Lancer

GPT-5.3 Codex 81.4% leads since February 2026
Fading

Models complete real Upwork software tasks, from bug fixes to features, and pick between engineering proposals. Scored by end-to-end tests and payout earned.

Only the Diamond split is public. Some cards report dollars earned rather than pass rate. Since July 17th, 2025 the public repo holds 198 of the 237 IC SWE Diamond tasks. OpenAI dropped 39 tasks that failed offline, so later scores use a smaller set.

Made by
OpenAI
Released
February 2025
Kind
Fixing real repositories
Level
Expert
Scored
Checked automatically
Answers
Code
Tasks
Public, plus a private test set
Strongest model tested
GPT-5 #70 on the capability index
Last in a launch post
February 2026, dropped before it saturated
Last model added
February 2026

In the authors’ words

We introduce SWE-Lancer, a benchmark of over 1,400 freelance software engineering tasks from Upwork, valued at $1 million USD total in real-world payouts. SWE-Lancer encompasses both independent engineering tasks–ranging from $50 bug fixes to $32,000 feature implementations–and managerial tasks, where models choose between technical implementation proposals. Independent tasks are graded with end-to-end tests triple-verified by experienced software engineers, while managerial decisions are assessed against the choices of the original hired engineering managers. We evaluate model performance and find that frontier models are still unable to solve the majority of tasks. To facilitate future research, we open-source a unified Docker image and a public evaluation split, SWE-Lancer Diamond (https://github.com/openai/SWELancer-Benchmark). By mapping model performance to monetary value, we hope SWE-Lancer enables greater research into the economic impact of AI model development.

Abstract of SWE-Lancer: Can Frontier LLMs Earn $1 Million from Real-World Freelance Software Engineering? (arXiv:2502.12115, CC0)
10
Models scored in lab cards
10
Launch posts list it, from 2 labs
9
System cards report it, from 3 labs

GPT-5.3 Codex leads with 81.4% among models released by February 2026

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.

The newest model with a score here came out in February 2026, and nobody has reported a newer one. Among the 20 highest-ranked models on the capability index, these have no score yet:

  1. 1 GPT-5.3 Codex 81.4%
  2. 2 GPT-5.1-Codex-Max 80%
  3. 3 GPT-5 55%
  4. 4 o3 54%
  5. 5 OpenAI deep research 53%
  6. 6 o4-mini 52%
  7. 7 GPT-5 mini 51%
  8. 8 Seed2.0 Pro 49.4%
  9. 9 Kimi K2 Jul 2025 39.1%
  10. 10 GPT-4.5 32.6%

Source: Labs’ model cards

#ModelScoreSettingDateSource
1 GPT-5.3 Codex 81.4% Feb 2026 Lab model card
2 GPT-5.1-Codex-Max 80% Nov 2025 Lab model card
3 GPT-5 55% Aug 2025 Lab model card
4 o3 54% Apr 2025 Lab model card
5 OpenAI deep research 53% Feb 2025 Lab model card
6 o4-mini 52% Apr 2025 Lab model card
7 GPT-5 mini 51% Aug 2025 Lab model card
8 Seed2.0 Pro 49.4% Feb 2026 Lab model card
9 Kimi K2 Jul 2025 39.1% Jul 2025 Lab model card
10 GPT-4.5 32.6% Feb 2025 Lab model card

5 models have held number one in labs’ own numbers since its release in February 2025

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

OpenAI
Lab claims Not tested since Feb 2026

Source: Labs’ model cards

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 Best so far
0% 20% 40% 60% 80% 100% 2025 2026 Near the ceiling (85%) GPT-5.3 Codex GPT-5.1-Codex-Max GPT-5 o3 0% 20% 40% 60% 80% 100% 2025 2026 Near the ceiling (85%) GPT-5.3 Codex GPT-5

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.

OpenAI
ByteDance Seed
DateLaunch postScoreAs the post writes it
Feb 14, 2026 Seed2.0 Pro 49.4 SWE-Lancer
Feb 5, 2026 GPT-5.3 Codex 81.4 SWE-Lancer IC Diamond
Nov 19, 2025 GPT-5.1-Codex-Max 79.9 SWE-Lancer IC SWE, xhigh
Aug 7, 2025 GPT-5 nano SWE-Lancer: IC SWE Diamond Freelance Coding Tasks ($49K)
Aug 7, 2025 GPT-5 mini SWE-Lancer: IC SWE Diamond Freelance Coding Tasks ($75K)
Apr 16, 2025 o4-mini SWE-Lancer: IC SWE Diamond (o4-mini-high), dollars earned
Apr 16, 2025 o3 SWE-Lancer: IC SWE Diamond (dollars earned), o3-high
Apr 14, 2025 GPT-4.1 nano 3.7 SWE-Lancer (IC-Diamond subset) $9K (3.7%)
Apr 14, 2025 GPT-4.1 mini 13.1 SWE-Lancer (IC-Diamond subset) $31K (13.1%)
Feb 27, 2025 GPT-4.5 32.6 SWE-Lancer Diamond (coding)*

9 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.

DateDocumentScoreAs the document writes itSection
Feb 14, 2026 Seed2.0 Pro model card 49.4 SWE-Lancer (Table 11) Capabilities
Nov 18, 2025 GPT-5.1-Codex-Max system card 80 SWE-Lancer IC SWE Diamond, pass@1 avg of 3, printed chart label (Figure 8, 5.1.3.1) AI R&D risk
Aug 7, 2025 GPT-5 system card 55 SWE-Lancer IC SWE Diamond, pass@1 avg of 3, no browsing launch candidate (Figure 24) AI R&D risk
Aug 7, 2025 GPT-5 mini system card 51 SWE-Lancer IC SWE Diamond, pass@1 avg of 3, gpt-5-thinking-mini launch candidate (Figure 24) AI R&D risk
Jul 21, 2025 Kimi K2 technical report 39.1 SWE-Lancer (Pass@1) (Table 3) Capabilities
Apr 16, 2025 o4-mini system card 52 SWE-Lancer Diamond (IC SWE), pass@1, o4-mini no browsing launch candidate, printed chart label (Figure 21) AI R&D risk
Apr 16, 2025 o3 system card 54 SWE-Lancer Diamond (IC SWE), pass@1, o3 no browsing launch candidate, printed chart label (Figure 21) AI R&D risk
Feb 27, 2025 GPT-4.5 system card 20 SWE-Lancer Diamond IC SWE tasks, pass@1, post-mitigation, earned $41,625 (4.6.6) Autonomy
Feb 25, 2025 OpenAI deep research system card 53 SWE-Lancer Diamond (IC SWE), pass@1 averaged over 3 runs, post-mitigation with browsing, $87,708 earned (without browsing 48%, $75,583), July 2025 dataset update (3.4.7) Autonomy

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