GPT-5.6 Luna vs Mistral Medium 3.5
Pricing verdict: GPT-5.6 Luna vs Mistral Medium 3.5: GPT-5.6 Luna is cheaper for input-heavy usage ($1.00/M vs $1.50/M input tokens), while GPT-5.6 Luna is better for long-context tasks (1,050,000 tokens).
Direct answer: choose GPT-5.6 Luna for lower token spend and choose GPT-5.6 Luna when your workload needs longer context.
Compare API pricing, input and output token costs, context windows, and monthly estimates on one page so you can pick the right model fast.
Cost Comparison (1000 input + 500 output tokens, 100 requests/day)
GPT-5.6 Luna
Mistral Medium 3.5
Cost Differences
Mistral Medium 3.5 costs more than GPT-5.6 Luna
Quick Recommendation
Winner for direct API pricing: GPT-5.6 Luna. At the default workload, GPT-5.6 Luna saves about $3.75/month ($45.625/year) versus Mistral Medium 3.5.
Feature Comparison
| Feature | GPT-5.6 Luna | Mistral Medium 3.5 |
|---|---|---|
| Provider | OpenAI | Mistral AI |
| Input Price | $1.00/1M tokens | $1.50/1M tokens |
| Output Price | $6.00/1M tokens | $7.50/1M tokens |
| Context Window | 1,050,000 tokens | 256,000 tokens |
| Max Output | 128,000 tokens | 32,768 tokens |
| Category | efficient | flagship |
| Capabilities | textvisioncodereasoning | textvisioncodereasoning |
| Release Date | 6/26/2026 | 4/29/2026 |
GPT-5.6 Luna vs Mistral Medium 3.5: Which Should You Choose?
Choosing between GPT-5.6 Luna and Mistral Medium 3.5 depends on your priorities: cost efficiency, context length, or raw capability. GPT-5.6 Luna is the more affordable option at $1.00/1M input tokens — 33% cheaper than Mistral Medium 3.5. Meanwhile, GPT-5.6 Luna offers a significantly larger context window at 1,050,000 tokens vs 256,000 for Mistral Medium 3.5.
These models come from different providers — OpenAI and Mistral AI — which means different API ecosystems, SDKs, rate limits, and terms of service. If you're already integrated with OpenAI, switching to Mistral AIinvolves migration effort beyond just pricing. Factor in your existing infrastructure when deciding.
These models target different tiers: GPT-5.6 Luna is a efficient model while Mistral Medium 3.5 is flagship. This means they're optimized for different workloads. Mistral Medium 3.5 targets more demanding workloads, while GPT-5.6 Luna provides a cost-effective option for everyday tasks.
Output costs matter too. GPT-5.6 Luna charges $6.00/1M output tokens vs $7.50 for Mistral Medium 3.5. For generation-heavy workloads (content creation, code generation, summarization), output pricing often dominates your bill. GPT-5.6 Luna has the edge here at $6.00/1M output tokens.
Multimodal capabilities: Both models support vision (image understanding), so you can send images alongside text prompts with either option.
Best Use Cases
Choose GPT-5.6 Luna when:
- • Budget is a primary concern
- • You need a larger context window (1,050,000 tokens)
- • You need longer outputs (up to 128,000 tokens)
- • You're already using OpenAI's API ecosystem
- • You're running high-volume, latency-sensitive workloads
Choose Mistral Medium 3.5 when:
- • You're already using Mistral AI's API ecosystem
Pros and Caveats at a Glance
GPT-5.6 Luna
- • Input pricing: $1.00/M tokens
- • Output pricing: $6.00/M tokens
- • Context window: 1,050,000 tokens
- • Max output: 128,000 tokens
Watch out for
- • Trade-offs are minor in this matchup.
Mistral Medium 3.5
- • Input pricing: $1.50/M tokens
- • Output pricing: $7.50/M tokens
- • Context window: 256,000 tokens
- • Max output: 32,768 tokens
Watch out for
- • Higher input cost than GPT-5.6 Luna
- • Higher output cost than GPT-5.6 Luna
- • Smaller context window than GPT-5.6 Luna
Try Different Scenarios
Use the calculator below to see how costs change with different usage patterns
GPT-5.6 Luna (OpenAI)
Mistral Medium 3.5 (Mistral AI)
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Sign Up for Mistral AI →Frequently Asked Questions
Which is cheaper, GPT-5.6 Luna or Mistral Medium 3.5?▼
What is the context window difference between GPT-5.6 Luna and Mistral Medium 3.5?▼
Which model is better for AI Agent / Agentic Workflows?▼
Which model has better overall pricing for heavy usage?▼
Where can I compare OpenAI and Mistral AI API pricing beyond this model matchup?▼
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