Claude Sonnet 4 - This is currently the best overall model for coding tasks.Gemini 2.5 Pro - Excellent quality but may have longer response times due to reasoning.If one isn’t giving you good results, try the other. Sometimes one model is good at a thing that the other model is bad at.
Note: Claude Sonnet 4 is a very eager model, and tries to run lots of actions.
OpenAI o3 - Takes time to think through problems but delivers often perfect results.o3 does not have access to tools in Alex, in order to keep the output quality high. So make sure to pass all the files it needs into its context first.
Here’s the ranking of all models available in Alex:
Claude Sonnet 4
Gemini 2.5 Pro
Claude 3.5 Sonnet
Gemini 2.5 Flash
OpenAI o3
OpenAI o4 Mini (06.19)
OpenAI GPT 4.1
DeepSeek R1
DeepSeek V3 (03.24)
These are just our rankings, based on our experience with general iOS/Swift development. For general SWE rankings, see Aider’s Leaderboard: https://aider.chat/docs/leaderboards/