Mellum 4B
Mellum 4B is a released coding model with open-source; evaluate it while provider pricing coverage matures.
Use it for
- Teams evaluating coding
- Workloads that can use a 8k context window
Do not use it for
- Cost-sensitive launches that need sourced token pricing
- Vision or document-understanding workloads
- Strict JSON or tool-calling flows
- Family
- Mellum
- Released
- 2025-04-30
- Context
- 8k
- Parameters
- 4B
- Architecture
- Decoder Only
- Specialization
- code
- Openness
- Open source
- License
- Apache 2.0OSI-approvedCommercial use: permitted
- Weights
- Available
- Code
- Unknown
- Training
- Pretrained
No tracked provider token pricing is available yet.
About
Mellum 4B is JetBrains' open-weights LLaMA-style code-completion model trained on roughly 4.2T tokens across permissively licensed code and Wikipedia. It is optimized for IDE code suggestions and local or self-hosted developer tooling.
Mellum 4B is an open-source model in the Mellum family. The structured metadata tracks a 8k-token context window. No headline benchmark score is tracked for Mellum 4B yet.
Top use-case fit: coding, agents, and build tasks
Coding
Included by capability and metadata signals in the decision map.
Provider price ladder
No tracked provider token pricing is available for this model yet.
Capabilities
No model capability flags are currently sourced.
Benchmark peer barsfor Coding
No task-mapped benchmark peers are available for this model yet.
Migration checks
No linked migration route is available for this model yet.
Frequently asked questions
What is the context window of Mellum 4B?
Mellum 4B has a context window of 8k tokens.
When was Mellum 4B released?
Mellum 4B was released on 2025-04-30.
No tracked provider token pricing is available yet.