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Devstral Medium vs GPT-6 Luna

GPT-6 Luna leads the LLM Stats Score 44.5 to 13.6. GPT-6 Luna is 4.0x cheaper per token.

Mistral AI · OpenAI · Updated for 2026

Which is better?

GPT-6 Luna leads the overall LLM Stats Score 44.5 to 13.6, ranking #41 overall.

On price, GPT-6 Luna is roughly 4.0x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

GPT-6 Luna also accepts a larger context window (1,050,000 input tokens), making it the stronger choice for long documents and large codebases.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Devstral Medium

  • you want predictable pricing at $0.40/M input and $2.00/M output

Choose GPT-6 Luna

  • overall performance matters — it scores 44.5 and ranks #41 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • cost matters — it's about 4.0x cheaper per token
  • you process long inputs — it offers a 1,050,000 token context window
  • you want the most recent training data — it shipped Sep 2026

At a glance

The differences that matter most.

Core performance indexes
13.6
#249
44.5
#41
13.5
#242
40.0
#58
5.3
#206
31.4
#47
Cost, coverage & limits
Benchmark wins
Input price
$0.40 / M
$0.10 / M
Output price
$2.00 / M
$0.50 / M
Context window
128,000
1,050,000

Individual benchmarks

1 reported for Devstral Medium · 5 for GPT-6 Luna

No common benchmarks found

Devstral Medium and GPT-6 Lunadon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

GPT-6 Luna costs less

For input processing, Devstral Medium ($0.40/1M tokens) is 4.0x more expensive than GPT-6 Luna ($0.10/1M tokens).

For output processing, Devstral Medium ($2.00/1M tokens) is 4.0x more expensive than GPT-6 Luna ($0.50/1M tokens).

In conclusion, Devstral Medium is more expensive than GPT-6 Luna.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Wed Sep 23 2026 • llm-stats.com
Mistral AI
Devstral Medium
Input tokens$0.40
Output tokens$2.00
Best providerMistral
OpenAI
GPT-6 Luna
Input tokens$0.10
Output tokens$0.50
Best providerOpenAI
Notice missing or incorrect data?Start an Issue

Context Window

Maximum input and output token capacity

GPT-6 Luna accepts 1,050,000 input tokens compared to Devstral Medium's 128,000 tokens. Both models can generate responses up to 128,000 tokens.

Mistral AI
Devstral Medium
Input128,000 tokens
Output128,000 tokens
OpenAI
GPT-6 Luna
Input1,050,000 tokens
Output128,000 tokens
Wed Sep 23 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

GPT-6 Luna supports multimodal inputs, whereas Devstral Medium does not.

GPT-6 Luna can handle both text and other forms of data like images, making it suitable for multimodal applications.

Devstral Medium

Text
Images
Audio
Video

GPT-6 Luna

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Devstral Medium

Proprietary

Closed source

GPT-6 Luna

Proprietary

Closed source

Release Timeline

When each model was launched

Devstral Medium was released on 2025-07-10, while GPT-6 Luna was released on 2026-09-22.

GPT-6 Luna is 15 months newer than Devstral Medium.

Devstral Medium

Jul 10, 2025

1.2 years ago

GPT-6 Luna

Sep 22, 2026

0 days ago

1.2yr newer

Knowledge Cutoff

When training data ends

GPT-6 Luna has a documented knowledge cutoff of 2026-05-18, while Devstral Medium's cutoff date is not specified.

We can confirm GPT-6 Luna's training data extends to 2026-05-18, but cannot make a direct comparison without Devstral Medium's cutoff date.

Devstral Medium

GPT-6 Luna

May 2026

Provider Availability

Devstral Medium is available from Mistral AI. GPT-6 Luna is available from OpenAI.

Devstral Medium

mistral logo
Mistral
Input Price:Input: $0.40/1MOutput Price:Output: $2.00/1M

GPT-6 Luna

openai logo
OpenAI
Input Price:Input: $0.10/1MOutput Price:Output: $0.50/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion

Judge for yourself.

Run your own prompts against Devstral Medium and GPT-6 Luna side-by-side, then vote on the output you prefer.

Devstral Medium
✓ Preferred
GPT-6 Luna
Open in Playground

FAQ

Common questions about Devstral Medium vs GPT-6 Luna.

Which is better, Devstral Medium or GPT-6 Luna?

GPT-6 Luna leads the LLM Stats Score 44.5 to 13.6. Devstral Medium is made by Mistral AI and GPT-6 Luna is made by OpenAI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Devstral Medium compare to GPT-6 Luna in benchmarks?

Devstral Medium scores SWE-Bench Verified: 61.6%. GPT-6 Luna scores DeepSWE 1.1: 66.6%, OSWorld 2.0: 52.7%, Agents' Last Exam: 50.9%, FrontierCode 1.1: 42.4%, AutomationBench v1.0.6: 20.7%.

Is Devstral Medium cheaper than GPT-6 Luna?

GPT-6 Luna is 4.0x cheaper for input tokens. Devstral Medium costs $0.40/M input and $2.00/M output via mistral. GPT-6 Luna costs $0.10/M input and $0.50/M output via openai.

What are the context window sizes for Devstral Medium and GPT-6 Luna?

Devstral Medium supports 128K tokens and GPT-6 Luna supports 1.1M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Devstral Medium and GPT-6 Luna?

Key differences include LLM Stats Score (13.6 vs 44.5), context window (128K vs 1.1M), input pricing ($0.40 vs $0.10/M), multimodal support (no vs yes). See the full comparison above for benchmark-by-benchmark results.

Who makes Devstral Medium and GPT-6 Luna?

Devstral Medium is developed by Mistral AI and GPT-6 Luna is developed by OpenAI.