Editing format

Aider uses different “edit formats” to collect code edits from different LLMs. The “whole” format is the easiest for an LLM to use, but it uses a lot of tokens and may limit how large a file can be edited. Models which can use one of the diff formats are much more efficient, using far fewer tokens. Models that use a diff-like format are able to edit larger files with less cost and without hitting token limits.

Aider is configured to use the best edit format for the popular OpenAI and Anthropic models and the other models recommended on the LLM page. For lesser known models aider will default to using the “whole” editing format since it is the easiest format for an LLM to use.

If you would like to experiment with the more advanced formats, you can use these switches: --edit-format diff or --edit-format udiff.