Benchmark Almanac

CanItEdit

Seed Diffusion Preview 54.3% leads since Jul 2025 Dropped

Models edit a given block of code to follow an instruction, such as adding a feature, fixing a described bug or changing the approach. Hidden tests check the edited code.

Labs report pass@1. ByteDance Seed reports it for Seed-Coder and Seed Diffusion Preview.

In the authors’ words

A significant amount of research is focused on developing and evaluating large language models for a variety of code synthesis tasks. These include synthesizing code from natural language, synthesizing tests from code, and synthesizing explanations of code. In contrast, the behavior of instructional code editing with LLMs is understudied. These are tasks in which the model is provided a block of code and an instruction to modify the code. The editing instruction may ask for a feature to be added or removed, describe a bug and ask for a fix, or ask for a different kind of solution. We introduce a carefully crafted benchmark of code editing tasks and use it to evaluate several cutting edge LLMs. Our evaluation exposes a significant gap between the capabilities of state-of-the-art open and closed models. For example, even GPT-3.5-Turbo is better than the best open model at code editing tasks. We also introduce a new, carefully curated, permissively licensed training dataset of code editing tasks coupled with natural language instructions. Using this training dataset, we show that we can fine-tune open Code LLMs to significantly improve their code editing capabilities, closing the gap between open and closed models. All code, data, and models are available at https://github.com/nuprl/CanItEdit.

Abstract of Can It Edit? Evaluating the Ability of Large Language Models to Follow Code Editing Instructions (arXiv:2312.12450, CC0)
Made by Northeastern University Programming Research Lab (Cassano et al.) Released Dec 2023 Function-level problems All tasks public Last in a launch post Jul 2025 , dropped before it saturated Last model added Aug 2025
Level
University Undergraduates and entry-level professionals
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.
3
Models scored in lab cards
2
Launch posts list it, from 2 labs
2
System cards report it, from 1 lab

Seed Diffusion Preview leads with 54.3% among models released by Jul 2025

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 Jul 2025, and nobody has reported a newer one. Among the 20 highest-ranked models on the capability index, these have no score yet:

  1. 1 Seed Diffusion Preview 54.3%
  2. 2 Codestral 50.5%
  3. 3 Seed-Coder-8B-Instruct 50.5%
#ModelScoreSettingDateSource
1 Seed Diffusion Preview 54.3% Jul 2025 Model card
2 Codestral 50.5% Jan 2025 Model card
3 Seed-Coder-8B-Instruct 50.5% Jun 2025 Model card

2 models have held number one since its release in Dec 2023

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

Mistral AI ByteDance Seed
Lab claims Not tested since Aug 2025

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 Near the ceiling (85%) Seed Diffusion Preview Codestral 0% 20% 40% 60% 80% 100% 2025 Near the ceiling (85%) Seed Diffusion Preview Codestral

No launch post has listed it since Jul 2025

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.

Mistral AI
ByteDance Seed
DateLaunch postScoreAs the post writes it
31 Jul 2025 Seed Diffusion Preview 54.3 CanItEdit pass@1
13 Jan 2025 Codestral 50.5 CanItEdit

2 system cards report it, from 1 lab

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
4 Aug 2025 Seed Diffusion Preview technical report 54.3 CanItEdit pass@1 (Table 1) Capabilities
4 Jun 2025 Seed-Coder-8B-Instruct technical report 50.5 CanItEdit pass@1 (Table 13) Capabilities

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