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Codium AI vs Mellum by JetBrains: Which is Better in 2026?

Choosing between Codium AI and Mellum by JetBrains comes down to understanding what each tool does best. This comparison breaks down the key differences so you can make an informed decision based on your specific needs, not marketing claims.

Bottom line: Codium AI wins this matchup. GitLab is our overall AI Coding pick. GitLab is our free AI Coding pick. Pick Mellum by JetBrains if you need its specific feature set.

··Methodology
Editor reviewed0 verified reviews comparedPricing checked Oct 2026

Short on time? Here's the quick answer

We've tested both tools. Here's who should pick what:

Codium AI

AI-powered test generation for code

Best for you if:

  • • You want a free tier before you commit
  • • You want aI test generation
  • • You want iDE integration

Mellum by JetBrains

AI coding assistant for JetBrains IDEs

Best for you if:

  • • You want deep integration with JetBrains IDEs for a seamless workflow
  • • You want significantly speeds up coding and reduces boilerplate
At a Glance
Codium AICodium AI
Mellum by JetBrainsMellum by JetBrains
Starts at
FreeFree tier available
Custom
Best For
AI CodingAI Coding
Rating
4.5/5-
Free plan
Yes No

Choose Codium AI or Mellum by JetBrains?

Codium AI

Choose Codium AI if

AI-powered test generation for code

  • You want a free tier before you commit
  • You want aI test generation
  • You want iDE integration
Mellum by JetBrains

Choose Mellum by JetBrains if

AI coding assistant for JetBrains IDEs

  • You want deep integration with JetBrains IDEs for a seamless workflow
  • You want significantly speeds up coding and reduces boilerplate
FeatureCodium AIMellum by JetBrains
Pricing ModelFreemiumPaid
User Rating
★4.5/5
120 reviews
No ratings yet
Categories
AI CodingTesting & QA
AI CodingDeveloper Tools

In-Depth Analysis

Codium AICodium AI

AI-powered test generation for code

Starts at Free
Good value

Codium AI's pricing is fair and generous for individual developers with a free tier offering 250 credits/month, but the Teams plan at $19/user/month is a strong value given its test generation and PR-Agent features.

Strengths

  • +AI test generation
  • +IDE integration
  • +Good for coverage
  • +Privacy options
  • +Free tier

Weaknesses

  • -Test quality varies
  • -Learning curve
  • -Language support varies
  • -Enterprise expensive
  • -Not replacement for manual

Key features

AI test generationCode analysisIDE pluginsMultiple languagesPR reviewEnterprise

Mellum by JetBrainsMellum by JetBrains

AI coding assistant for JetBrains IDEs

Starts at Custom

Strengths

  • +Deep integration with JetBrains IDEs for a seamless workflow.
  • +Significantly speeds up coding and reduces boilerplate.
  • +Helps developers understand unfamiliar codebases quickly.
  • +Improves code quality through intelligent suggestions and refactoring.

Weaknesses

  • -Requires an existing JetBrains IDE subscription.
  • -May have a learning curve for optimal utilization of AI features.
  • -Reliance on AI might reduce deep understanding of certain code segments over time.

Key features

Context-aware code completionCode generation from natural languageCode explanation and documentation generationRefactoring assistanceAI chat within the IDESupport for multiple programming languages and frameworks

Pricing: Codium AI vs Mellum by JetBrains

PlanCodium AIMellum by JetBrains
Tier 1
Free
Developer
N/A
Tier 2
$19 month per user
Teams
N/A
Tier 3
custom
Enterprise
N/A

Pricing verified from each vendor's public pricing page. Compare in detail on Codium AI pricing and Mellum by JetBrains pricing.

Who Should Use What?

On a budget?

Codium AI has a free tier. Mellum by JetBrains is paid only.

Go with: Codium AI

Want the highest-rated option?

Codium AI is rated 4.5/5. Mellum by JetBrains has no ratings yet.

Go with: Codium AI

Value user reviews?

Codium AI: 120 reviews (4.5/5). Mellum by JetBrains: no ratings yet.

Go with: Codium AI

3 Questions to Help You Decide

1

What's your budget?

Codium AI is freemium. Mellum by JetBrains is paid. Codium AI lets you start free.

2

What's your use case?

Both are ai coding tools. Compare their specific features to decide.

3

How important are ratings?

Codium AI is rated 4.5/5; Mellum by JetBrains has no ratings yet.

Key Takeaways

Codium AI

  • Free tier available
  • Our pick for this comparison

Mellum by JetBrains

  • Choose if you want aI coding assistant for JetBrains IDEs

The Bottom Line

Codium AI wins this matchup. GitLab is our overall AI Coding pick. GitLab is our free AI Coding pick.

Frequently Asked Questions

Is Codium AI or Mellum by JetBrains better?

Codium AI is rated in our evaluation. Codium AI is freemium and Mellum by JetBrains is paid.

What are Codium AI and Mellum by JetBrains used for?

Codium AI: AI-powered test generation for code. Mellum by JetBrains: AI coding assistant for JetBrains IDEs.

What does Codium AI cost vs Mellum by JetBrains?

Codium AI is freemium (free tier + paid plans). Mellum by JetBrains is a paid tool. Visit their websites for detailed pricing.

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