9 tools you can use instead of GPT-5.3 Codex, ranked by live GitHub stars and npm downloads. Anthropic Claude, StarCoder and Gemma 4 are the most used. Stats updated 5 hours ago.
Devstral is the closest open-weight alternative, built by Mistral AI for coding and software engineering agents. Anthropic Claude and Gemini 3.1 Pro are general-purpose hosted models, and StarCoder is an older open source code model.
GPT-5.3 Codex is OpenAI's specialized coding model, offered through the OpenAI API alongside general-purpose GPT models. It's priced at $1.75 per million input tokens and $14.00 per million output tokens in standard mode, with a faster mode available at higher per-token rates.
It is a weaker choice for:
Most used first.
Anthropic's Claude model family, accessed through the Claude apps, the Claude API, or major clouds.
Open source code-generation model from the BigCode project, trained on 80+ programming languages.
Google DeepMind's current generation of lightweight, open-weight language models.
DeepSeek's current open-weight model family, including V4.1-Flash and V4-Pro.
Mistral AI's open-weight model built specifically for coding and software engineering agents.
Google's third-generation Gemini Pro model, currently in preview, for complex reasoning tasks.
TypeSafe AI's System One model: returns typed decisions with probabilities instead of text.
Meta's proprietary flagship AI model, its first major release since the Llama line.
Mistral AI's flagship large language model for complex reasoning and general-purpose tasks.
| Tool | Pricing | Free plan | Paid from | Open source | GitHub stars |
|---|---|---|---|---|---|
| GPT-5.3 Codex | Pay as you go | No free tier for API access; usable through ChatGPT plans with usage limits | $1.75 per million input tokens (standard mode) | No | None |
| Anthropic Claude | Pay as you go | Yes, in the Claude apps; the API has no free tier and is billed per token | $20 a month for Claude Pro; API from $1 input per million tokens on Haiku 4.5 | No | 2.1k |
| StarCoder | Open source | Yes, free to download and use, subject to accepting the OpenRAIL-M license terms | Not listed | Yes, BigCode OpenRAIL-M | 7.5k |
| Gemma 4 | Open source | Yes, weights are free to download and run | Not listed | No | 5.8k |
| DeepSeek V4 | Open source | Yes, open-weight models free to download and self-host; API access is pay-as-you-go | $0.15 per million input tokens off-peak (V4.1-Flash, cache miss) | Yes, MIT (weights and code) | None |
| Devstral | Open source | Yes, open-weight model free to download and self-host; API access is pay-as-you-go | Priced per million tokens via Mistral's API; see Mistral's pricing page for current rates | Yes, Apache-2.0 | None |
| Gemini 3.1 Pro | Pay as you go | Limited free access is available through Google AI Studio and Gemini app tiers | $2.00 per million input tokens (up to 200k tokens) | No | None |
| Jev | Pay as you go | Not stated on the official site. Usage is billed per input token. | $0.042 per million input tokens; output tokens are free | No | None |
| Meta Muse Spark | Pay as you go | Access is available through Meta AI's consumer products with usage limits | Priced per million tokens via API partners; check current provider pricing | No | None |
| Mistral Large 3 | Pay as you go | Limited free access is available through La Plateforme's free tier | Around $0.50 per million input tokens (Mistral Large tier, per Mistral's example pricing) | No | None |
Pricing facts come from each tool's official pricing page, with the checked date on the tool's own page.
By GitHub stars, Anthropic Claude is the most used alternative to GPT-5.3 Codex listed on ScratchDB, with 2.1k stars.
StarCoder, DeepSeek V4 and Devstral are open source.
Anthropic Claude, StarCoder, Gemma 4, DeepSeek V4 and Devstral have a free plan. The table on this page shows what each one includes.
