LLM Reference

Mellum Models by JetBrains

JetBrainsApache 2.0
1 model2025Up to 8k ctx

About

Mellum is JetBrains' open-weights 4B code-completion model family, trained from scratch for professional developer tooling and optimized for IDE code suggestions.

Current Variants

Use-when guidance is derived from seed capabilities, context, release, and replacement fields.

1 in view
Mellum 4BCurrent

Use when the workload needs code, 8k context, and 4B parameters.

2025-04code8k context4B parameters

Release Timeline

1 release group
2025-04
1 current
Mellum 4B
code8k context4B parameters
Current

Specifications(1 models)

Mellum model specifications comparison
ModelReleasedContextParameters
Mellum 4B2025-048k4B

Frequently Asked Questions

What is Mellum used for?
Mellum is used for code and coding. The family description and listed model capabilities point to those workloads as the best fit.
How does Mellum compare to Mellum 2?
Mellum by JetBrains is strongest where you need code, while Mellum 2 by JetBrains is the closest related family to check for code. Mellum has 1 listed variant and reaches up to 8k context, while Mellum 2 reaches up to 131k context, so compare the specs and pricing tables before choosing a production model.
Which Mellum model should I use?
If price is the main constraint, use the pricing table first because Mellum does not have complete provider pricing in the local data. For the most capable/latest local choice, evaluate Mellum 4B with 8k context.

Models(1)