Best GPT-5.3-Codex alternatives
Users often look for alternatives to GPT-5.3-Codex when seeking faster output speeds, lower pricing, larger context windows, or open-weight options while retaining multimodal coding support. This list details seven models with their intelligence indices, speeds, costs, and context sizes compared directly to the base model's 44.3 index, 79.41 t/s speed, $14/1M price, and 400k context.
OpenAI's multimodal model for large-scale text, image and file tasks.
It provides close intelligence at 43.7 with 1M context but at slower 41.93 t/s speed and higher $25/1M cost from Anthropic.
This alternative handles similar 400k multimodal inputs at higher $120/1M cost with unspecified speed and intelligence from the same OpenAI provider.
Processes over a million tokens across images, text, and files.
This Google model expands to 1M context supporting more modalities at $10/1M but leaves intelligence and speed unspecified.
It delivers faster 147.78 t/s speed and lower $1.25/1M price with matching 400k context at a reduced 38.2 intelligence index from OpenAI.
It offers a much larger 10M context and faster 109.63 t/s speed at far lower $0.3/1M cost but with significantly lower 10 intelligence index as an open-weight Meta model.
It features a larger 1M context and lower $0.4/1M price with broad multimodal support though intelligence is only 13.1 from Google.
Frequently asked questions
Claude Opus 4.6 is the closest match with a 43.7 intelligence index, 1M context window, and strong reasoning strengths while remaining proprietary.