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Leanstral Pricing 2026

Complete pricing guide for Leanstral — plans, costs, and free options.

FreemiumFree API endpoint at launch. Available in Mistral Vibe (zero-setup). Open weights under Apache 2.0 for self-hosting.Updated June 14, 2026

💰 Leanstral Pricing Overview

Leanstral uses a freemium pricing model. Free tier available with optional paid upgrades. Current pricing: Free API endpoint at launch. Available in Mistral Vibe (zero-setup). Open weights under Apache 2.0 for self-hosting.. Leanstral is a popular coding & development tool known for mistral's open-source lean 4 proof agent — formal verification at low cost. You can get started with Leanstral for free and upgrade to a paid plan as your needs grow.

🔍 Compare Before You Buy

Comparing Leanstral to similar tools helps you make the best choice for your budget and needs:

GitHub Copilot

Paid

AI pair programmer for code suggestions

Starting at $10/month

Compare with Leanstral

Claude Opus 4.8

Paid

Anthropic's flagship model — stronger coding, agents, and honesty

Starting at $5/month

Compare with Leanstral

Devstral 2

Freemium

Mistral's SOTA open-weight coding model — 72.2% SWE-bench, free API

Devstral 2 (123B) and Devstral Small 2 (24B) are currently free to use via the Mistral API (console.mistral.ai). Open weights: Devstral 2 ships under a modified MIT license; Devstral Small 2 under Apache 2.0. Self-hosting on compatible hardware is supported. Enterprise pricing available for on-prem deployments.

Compare with Leanstral

Leanstral Plans & Pricing

Free

$0forever

API endpoint at launch

* Pricing information is based on publicly available data and may not reflect current promotions, annual discounts, or regional pricing. Visit the official Leanstral website for the latest pricing.

Is Leanstral Free?

Yes, Leanstral offers a free plan

Leanstral offers a free tier that lets you try the platform without any payment. The free plan typically includes core features with usage limits.

Is Leanstral Worth It?

Leanstral is a freemium coding & development tool that offers 9 key features including 120B total parameters, 6B active (sparse MoE) — efficient inference at scale, Apache 2.0 open weights — full self-hosting permitted, Free API endpoint via Mistral La Plateforme. Leanstral is Mistral AI's open-source code agent purpose-built for Lean 4, the proof assistant used for formal verification of mathematics and mission-critical software. Released March 16, 2026, it's a 120B-parameter sparse MoE model with 6B active parameters — designed to operate in realistic formal repositories, not just isolated math competition problems. Apache 2.0 license, free API endpoint, and integrated into Mistral Vibe for zero-setup use.

Leanstral is a good choice if you need:

  • 120B total parameters, 6B active (sparse MoE) — efficient inference at scale
  • Apache 2.0 open weights — full self-hosting permitted
  • Free API endpoint via Mistral La Plateforme
  • Zero-setup integration in Mistral Vibe via /leanstall command
  • MCP support: trained to maximize performance with lean-lsp-mcp

💡 Value Assessment

With a free tier available, Leanstral is an easy recommendation for anyone looking to try coding & development tools without financial commitment. The paid plans offer good value for power users who need the additional features and higher usage limits.

Leanstral Key Features

Leanstral comes packed with features that make it a strong contender in the coding & development space. Here's what you get:

1.
120B total parameters, 6B active (sparse MoE) — efficient inference at scale

Available in the free plan with limits — 120B total parameters, 6B active (sparse MoE) — efficient inference at scale helps you work more efficiently with Leanstral.

2.
Apache 2.0 open weights — full self-hosting permitted

Available in the free plan with limits — Apache 2.0 open weights — full self-hosting permitted helps you work more efficiently with Leanstral.

3.
Free API endpoint via Mistral La Plateforme

Integrate Leanstral into your own applications and workflows via the API.

4.
Zero-setup integration in Mistral Vibe via /leanstall command

Connect with your existing tools and services for a unified workflow.

5.
MCP support: trained to maximize performance with lean-lsp-mcp

Powered by advanced AI models, Leanstral delivers intelligent content generation capabilities.

6.
FLTEval benchmark: 26.3 at pass@2 — beats Claude Sonnet 4.6 (23.7) at 1/15th the cost

Available in the free plan with limits — FLTEval benchmark: 26.3 at pass@2 — beats Claude Sonnet 4.6 (23.7) at 1/15th the cost helps you work more efficiently with Leanstral.

7.
At pass@16, reaches 31.9 — beats Sonnet by 8 points and Haiku by 8.9 points

Powered by advanced AI models, Leanstral delivers intelligent content generation capabilities.

8.
Outperforms Qwen3.5-397B-A17B and Kimi-K2.5-1T-A32B despite far fewer active parameters

Available in the free plan with limits — Outperforms Qwen3.5-397B-A17B and Kimi-K2.5-1T-A32B despite far fewer active parameters helps you work more efficiently with Leanstral.

9.
New FLTEval evaluation suite for real proof engineering (FLT project PRs), not just competition math

Available in the free plan with limits — New FLTEval evaluation suite for real proof engineering (FLT project PRs), not just competition math helps you work more efficiently with Leanstral.

Leanstral Alternatives & Their Pricing

Considering alternatives to Leanstral? Here's how competing tools compare on pricing:

GitHub Copilot

Paid

AI pair programmer for code suggestions

Pricing: Individual $10/mo, Business $19/user/mo, Enterprise $39/user/mo

Claude Opus 4.8

Paid

Anthropic's flagship model — stronger coding, agents, and honesty

Pricing: $5/M input tokens, $25/M output tokens (standard). $10/M input, $50/M output (fast mode). Same pricing as Opus 4.7.

Devstral 2

Freemium

Mistral's SOTA open-weight coding model — 72.2% SWE-bench, free API

Pricing: Devstral 2 (123B) and Devstral Small 2 (24B) are currently free to use via the Mistral API (console.mistral.ai). Open weights: Devstral 2 ships under a modified MIT license; Devstral Small 2 under Apache 2.0. Self-hosting on compatible hardware is supported. Enterprise pricing available for on-prem deployments.

Ready to try Leanstral?

Visit the official website for the latest pricing and to get started.

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Frequently Asked Questions

Is Leanstral free to use?

Yes, Leanstral offers a free tier that you can use without paying. The free version includes core functionality.

How much does Leanstral cost in 2026?

As of 2026, Leanstral pricing is: Free API endpoint at launch. Available in Mistral Vibe (zero-setup). Open weights under Apache 2.0 for self-hosting.. Pricing may vary based on billing cycle (monthly vs annual) and region. Visit the official Leanstral website for the most current pricing.

What are the best alternatives to Leanstral?

Popular alternatives to Leanstral include GitHub Copilot, Claude Opus 4.8, Devstral 2. Each offers different features and pricing structures. Compare them on AISO Tools to find the best fit for your needs and budget.

Is Leanstral worth the price?

Leanstral is well-regarded in the coding space, offering features like 120B total parameters, 6B active (sparse MoE) — efficient inference at scale, Apache 2.0 open weights — full self-hosting permitted, Free API endpoint via Mistral La Plateforme. Whether it's worth the investment depends on your specific needs, usage volume, and budget. The free tier lets you try it before committing to a paid plan.

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