Mellum-4b-base is JetBrains' first open-source large language model (LLM) optimized for code-related tasks.
Czechia
EU
OpenAI Codex AlternativesOnly apps from the EU
The best alternative to OpenAI Codex is Mellum, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 50 alternatives to OpenAI Codex and seven of them are so hopefully you can find a suitable replacement. Other interesting alternatives to OpenAI Codex are Mistral Code, JetBrains Junie, JetBrains AI Assistant and Hostinger Horizons.
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OpenAI Codex alternatives are mainly AI Coding Assistants, but if you're looking for AI Writing Tools or Large Language Model (LLM) Tools you can filter on that. Other popular filters include Open Source. You can also filter by region, for example EU-based alternatives if you prefer software developed in the European Union. These are just examples - use the filter bar below to find more specific alternatives to OpenAI Codex.
Alternatives list
Lightning-fast completions, deep code understanding, and agentic software engineering—right where you work.
+4
44 JetBrains Junie alternativesYou think it, Junie helps make it happen – right in your IDE. Available on IntelliJ IDEA, PyCharm, WebStorm and .
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74 JetBrains AI Assistant alternativesWith JetBrains AI, your favorite tools gain new abilities while you are empowered with more information at your fingertips.
Cost / License
- Freemium
- Proprietary
Application type
Platforms
- JetBrains Rider
- CLion
- IntelliJ IDEA
- Pycharm
- PhpStorm
- RubyMine
- WebStorm
- ReSharper
71 Hostinger Horizons alternativesAI-driven no-code platform to create full-stack web apps quickly, featuring instant one-click deployment, integrated hosting, domain tools, professional email, real-time editing, version control, and rapid live publishing with a streamlined three-step process.
Cost / License
- Paid
- Proprietary
Platforms
- Online
- Software as a Service (SaaS)
+2
Frontman is an AI Agent that lives in your browser, sees your live DOM, and turns your visual feedback into real changes - no more refresh-and-check cycles.
Cost / License
- Paid
- Open Source
Platforms
- Online
- Next.js
- Wordpress
ShaggAi is a local-first AI automation and autocomplete platform that turns natural language into real actions on your PC and adds Copilot-style “ghost text” to almost any editor.
Cost / License
- Freemium
- Proprietary
Platforms
- Windows
- Linux
+2
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