Compare / Mistral Medium 3.5 vs o3
Mistral Medium 3.5 vs o3
Which is cheaper, which is more capable, and which does better at each kind of work, from 19 results on 3 sources that measured both models.
Mistral Medium 3.5 or o3? The short answer
- Mistral Medium 3.5 is cheaper: $3.00 against $3.50 per million tokens, 14% less.
- o3 scores higher on the Artificial Analysis Intelligence Index: 20.2 against 14.2.
- Mistral Medium 3.5 writes faster: 163 tokens a second against 126.
- On our business benchmarks, o3 ranks higher for agents and tool use, reasoning and knowledge, writing and sticking to the facts.
At a glance
| Mistral Medium 3.5 | o3 | |
|---|---|---|
| Price per million tokens | $1.50 in · $7.50 out | $2.00 in · $8.00 out |
| Blended (3 in : 1 out) | $3.00 | $3.50 |
| Cheapest host, blended | $3.00 (Mistral) | – |
| Intelligence Index | 14.2 | 20.2 |
| Spring Prompt overall | 21 | – |
| Output speed, tokens a second | 163 | 126 |
| Context window | 262,144 tokens | 200,000 tokens |
| Weights | Closed | Closed |
| Developer based in | France | the US |
Prices are the developer's list price where we have read it, otherwise the typical host on OpenRouter; see every model's price. Intelligence and speed from Artificial Analysis.
Which is better for what
Each model's rank among models available today, for each kind of work, from our own benchmarks and licensed sources. The better rank is in green.
| Use case | Mistral Medium 3.5 | o3 |
|---|---|---|
| Product listingsTurning a sparse product feed and photos into listings that can go live | 13 of 19 | not measured |
| Decks from an analysisTurning a finished analysis into a deck you could present as it is | 14 of 18 | not measured |
| Marketing planningPlanning a year of ad spend without overspending | 18 of 18 | not measured |
| Agents and tool useMulti-step tasks with tools: support desks, coding agents, function calls | 87 of 161 | 13 of 161 |
| Reasoning and knowledgeHard questions across science, maths and general knowledge | 119 of 195 | 95 of 195 |
| WritingWhat people prefer in blind comparisons, and judged writing quality | 85 of 187 | 49 of 187 |
| Sticking to the factsSummarising without inventing things, and factual answers | 99 of 153 | 91 of 153 |
| Speed under pressureGood decisions against a real clock (fast chess) | 8 of 21 | not measured |
From our research
Every shared result
| Benchmark | Metric | Mistral Medium 3.5 | o3 |
|---|---|---|---|
| Arena (formerly LMArena)reported | OverallArena rating | 1,430 | 1,405 |
| Arena (formerly LMArena)reported | Business, management and financeArena rating | 1,430 | 1,426 |
| Arena (formerly LMArena)reported | Creative writingArena rating | 1,398 | 1,383 |
| Arena (formerly LMArena)reported | Expert promptsArena rating | 1,434 | 1,449 |
| Arena (formerly LMArena)reported | Instruction followingArena rating | 1,421 | 1,403 |
| Arena (formerly LMArena)reported | OverallArena rating | 1,426 | 1,432 |
| Arena (formerly LMArena)reported | Writing, literature and languageArena rating | 1,404 | 1,396 |
| Artificial Analysisreported | Artificial Analysis Intelligence Indexindex score | 14.2 | 20.2 |
| Artificial Analysisreported | GPQA Diamond% of questions | 74.8% | 82.7% |
| Artificial Analysisreported | Humanity's Last Exam% of questions | 13.8% | 20.1% |
| Artificial Analysisreported | IFBench% of instructions | 68.8% | 71.4% |
| Artificial Analysisreported | Long-context reasoning (AA-LCR)% of questions | 69.3% | 74.7% |
| Artificial Analysisreported | Output speedtokens per second | 163 | 126 |
| Artificial Analysisreported | Terminal-Bench Hard% of tasks | 33.3% | 37.1% |
| Artificial Analysisreported | Time to first answer tokenseconds | 12.9 | 3.96 |
| Artificial Analysisreported | Τ²-bench telecom% of tasks | 94.2% | 80.7% |
| UGI Leaderboardreported | Requested-length error% off the requested word count | 18.0% | 18.0% |
| UGI Leaderboardreported | Style adherencescore from 0 to 1 | 0.35 | 0.30 |
| UGI Leaderboardreported | Writing scorescore out of 100 | 45.5 | 66.8 |
Bold green marks the better value on that metric. Where a source reports ranges that overlap, the difference may not be meaningful; see the benchmark page for ranges.
Quick answers
Is Mistral Medium 3.5 better than o3?
It depends on the task. Among models available today, on our benchmarks and licensed sources, o3 ranks higher for agents and tool use, reasoning and knowledge, writing and sticking to the facts.
Which is cheaper, Mistral Medium 3.5 or o3?
Mistral Medium 3.5 costs $3.00 per million tokens (three input to one output), against $3.50 for o3.
Which is faster, Mistral Medium 3.5 or o3?
Mistral Medium 3.5 writes about 163 tokens a second on its usual API, against 126 for o3 (Artificial Analysis).
Run Mistral Medium 3.5 and o3 on your own prompt
Benchmarks aren't your data. Try both side by side in the playground, with the cost of every answer.