Claude Opus 4.5 vs Mistral Medium 3.1

Claude Opus 4.5 leads Mistral Medium 3.1 on the Artificial Analysis Intelligence Index, 29.1 to 9.2, and Mistral Medium 3.1 costs 12.5x less per output token ($2.00 vs $25.00 per million). Updated October 21, 2026; 59 benchmarks have a result for both.

Replace Claude Opus 4.5 Replace Mistral Medium 3.1

Claude Opus 4.5Anthropic

Coding: 44.0
Overall: 55.7
Output $/M: $25.00

Mistral Medium 3.1Mistral AI

Coding: No data
Overall: No data
Output $/M: $2.00

vs boards won of 59 shared

Claude Opus 4.5 or Mistral Medium 3.1: which to pick

Only Claude Opus 4.5 has a coding score, 44.0 on the Vibe Coding Index; Mistral Medium 3.1 has none, so the two cannot be ranked on coding.

Pick Mistral Medium 3.1 for output tokens 12.5x cheaper ($2.00 vs $25.00 per million) and work measured by LMArena Text: medicine and healthcare, where it leads.

Model AClaude Opus 4.5Anthropic44.0/1003 independent benchmarks$1.37 per solved task Model BMistral Medium 3.1Mistral AINot benchmarkedNo coding benchmarkNo cost per solved task

594915

Shared results: 59
Claude Opus 4.5 only: 49
Mistral Medium 3.1 only: 15
Like-for-like categories: 8 of 9

Only benchmarks that tested both models count toward a pick; a result only one model has is shown but not compared.

Which one for your work

Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.

Coding
Vibe Coding Index, six public coding benchmarks
No call
Only Claude Opus 4.5 has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
Claude Opus 4.5
Claude Opus 4.5 leads, 29.1 against 9.2.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only Mistral Medium 3.1 has a AA Agentic Index result, 1.9.
Directional only
Reasoning
GPQA Diamond
No call
Only Claude Opus 4.5 has a GPQA Diamond result, 85.9%.
Directional only
Math
AIME
Claude Opus 4.5
Claude Opus 4.5 leads, 95.4% against 42.3%.
Same board, both measured
Knowledge
MMLU Pro
Claude Opus 4.5
Claude Opus 4.5 leads, 87.3% against 75.3%.
Same board, both measured
Web design
Design Arena: websites
Claude Opus 4.5
Claude Opus 4.5 leads, 1247 against 1133.
Same board, both measured
Long documents
Listed context window
Claude Opus 4.5
Claude Opus 4.5 takes 200K tokens against 131K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Mistral Medium 3.1
Claude Opus 4.5 $0.018, Mistral Medium 3.1 $0.0014 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Claude Opus 4.5 has the number, $1.37.
Directional only

At a glance

Coding index: Claude Opus 4.5 44.0 from 3 benchmarks, Mistral Medium 3.1 not benchmarked.
Widest category: Agentic work, 48.8 points apart on average over 1 shared benchmark.
Widest single gap: AIME: Claude Opus 4.5 95.4% against Mistral Medium 3.1 42.3%, 53.1 points apart on a 0 to 100 scale.
Output price: Claude Opus 4.5 $25.00 against Mistral Medium 3.1 $2.00 per million output tokens, 12.5x apart.
Context window: Claude Opus 4.5 takes 200K tokens, Mistral Medium 3.1 131K.

Benchmark by benchmark

First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.

Boards won, where both have a result
Category	Claude Opus 4.5	Mistral Medium 3.1
Coding	5	0
Intelligence	1	0
Agentic work	1	0
Reasoning	6	0
Math	6	0
Knowledge	10	1
Web design	8	0
General	21	0
All shared boards	58	1

CodingLike-for-likeSix of these boards feed the Vibe Coding Index50

Coding benchmarks for Claude Opus 4.5 and Mistral Medium 3.1
Benchmark	Claude Opus 4.5	Mistral Medium 3.1	Leader
SWE-bench Verified	79.2%	Not measured	Only Claude Opus 4.5 measured
SWE-bench (full test set)	52.6%	Not measured	Only Claude Opus 4.5 measured
SWE-bench Multilingual	70.7%	Not measured	Only Claude Opus 4.5 measured
LMArena WebDev	1494	Not measured	Only Claude Opus 4.5 measured
AA Coding Index	Not measured	20.5	Only Mistral Medium 3.1 measured
LiveCodeBench (Vals AI)	83.7%	44.8%	Claude Opus 4.5
SWE-bench Verified (Vals AI)	76.4%	Not measured	Only Claude Opus 4.5 measured
Vibe Code Bench (Vals AI)	20.6%	Not measured	Only Claude Opus 4.5 measured
LiveCodeBench (Artificial Analysis run)	87.1%	40.6%	Claude Opus 4.5
SciCode	Not measured	32.4%	Only Mistral Medium 3.1 measured
Terminal-Bench Hard (Artificial Analysis run)	47.0%	10.6%	Claude Opus 4.5
Terminal-Bench	63.1%	Not measured	Only Claude Opus 4.5 measured
GSO-Bench	26.5%	Not measured	Only Claude Opus 4.5 measured
WeirdML	63.7%	Not measured	Only Claude Opus 4.5 measured
Cybench	82.0%	Not measured	Only Claude Opus 4.5 measured
ALE-Bench	Not measured	210.2	Only Mistral Medium 3.1 measured
LMArena Text: coding	1503	1433	Claude Opus 4.5
LMArena Text: software and IT	1483	1436	Claude Opus 4.5
LMArena WebDev: React	1478	Not measured	Only Claude Opus 4.5 measured
LMArena WebDev: HTML	1510	Not measured	Only Claude Opus 4.5 measured
Neither model has a result on the other 19 boards here

IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10

Intelligence benchmarks for Claude Opus 4.5 and Mistral Medium 3.1
Benchmark	Claude Opus 4.5	Mistral Medium 3.1	Leader
AA Intelligence Index	29.1	9.2	Claude Opus 4.5
Epoch Capabilities Index	150.1	Not measured	Only Claude Opus 4.5 measured

Agentic workLike-for-likePublic boards, shown as published, kept out of the index10

Agentic work benchmarks for Claude Opus 4.5 and Mistral Medium 3.1
Benchmark	Claude Opus 4.5	Mistral Medium 3.1	Leader
AA Agentic Index	Not measured	1.9	Only Mistral Medium 3.1 measured
Design Arena: agents building web apps	1159	Not measured	Only Claude Opus 4.5 measured
Design Arena: agents building full-stack apps	1156	Not measured	Only Claude Opus 4.5 measured
Design Arena: agents building mobile apps	1189	Not measured	Only Claude Opus 4.5 measured
Design Arena: agents building Android apps	1175	Not measured	Only Claude Opus 4.5 measured
τ²-Bench Telecom	89.5%	40.6%	Claude Opus 4.5
METR time horizons	75.0%	Not measured	Only Claude Opus 4.5 measured
Remote Labor Index	3.8%	Not measured	Only Claude Opus 4.5 measured
GDPval	45.5%	Not measured	Only Claude Opus 4.5 measured
BALROG	43.5%	Not measured	Only Claude Opus 4.5 measured
DeepResearch Bench	54.8%	Not measured	Only Claude Opus 4.5 measured
OSWorld	66.3%	Not measured	Only Claude Opus 4.5 measured
Vending-Bench 2	$4,967	Not measured	Only Claude Opus 4.5 measured
Berkeley Function Calling Leaderboard (BFCL)	77.5%	Not measured	Only Claude Opus 4.5 measured
Neither model has a result on the other 27 boards here

ReasoningLike-for-likePublic boards, shown as published, kept out of the index60

Reasoning benchmarks for Claude Opus 4.5 and Mistral Medium 3.1
Benchmark	Claude Opus 4.5	Mistral Medium 3.1	Leader
GPQA Diamond	85.9%	Not measured	Only Claude Opus 4.5 measured
MMMU Pro (Vals AI)	83.0%	63.0%	Claude Opus 4.5
GPQA Diamond (Artificial Analysis run)	86.6%	58.8%	Claude Opus 4.5
Humanity's Last Exam (Artificial Analysis run)	30.1%	4.7%	Claude Opus 4.5
GPQA Diamond (Epoch AI run)	86.0%	Not measured	Only Claude Opus 4.5 measured
ARC-AGI	80.0%	Not measured	Only Claude Opus 4.5 measured
ARC-AGI-2	37.6%	Not measured	Only Claude Opus 4.5 measured
SimpleBench	62.0%	Not measured	Only Claude Opus 4.5 measured
Chess puzzles	14.0%	Not measured	Only Claude Opus 4.5 measured
Mystery game puzzles	22.0%	Not measured	Only Claude Opus 4.5 measured
EBR-bench	14.3%	Not measured	Only Claude Opus 4.5 measured
VPCT	40.0%	Not measured	Only Claude Opus 4.5 measured
LMArena Text: hard prompts	1476	1426	Claude Opus 4.5
LMArena Text: expert	1487	1408	Claude Opus 4.5
LMArena Text: hard prompts in English	1482	1435	Claude Opus 4.5
LMArena Vision: diagrams	Not measured	1175	Only Mistral Medium 3.1 measured
LMArena Vision: homework	Not measured	1165	Only Mistral Medium 3.1 measured
Kagi LLM Benchmark	80.2%	Not measured	Only Claude Opus 4.5 measured
Neither model has a result on the other 4 boards here

MathLike-for-likePublic boards, shown as published, kept out of the index60

Math benchmarks for Claude Opus 4.5 and Mistral Medium 3.1
Benchmark	Claude Opus 4.5	Mistral Medium 3.1	Leader
AIME	95.4%	42.3%	Claude Opus 4.5
MATH 500 (Vals AI)	Not measured	87.0%	Only Mistral Medium 3.1 measured
MGSM (Vals AI)	95.2%	90.9%	Claude Opus 4.5
AA Math Index	91.3	38.3	Claude Opus 4.5
AIME 2025 (Artificial Analysis run)	91.3%	38.3%	Claude Opus 4.5
OTIS Mock AIME	86.1%	Not measured	Only Claude Opus 4.5 measured
FrontierMath, tiers 1 to 3	34.4%	Not measured	Only Claude Opus 4.5 measured
FrontierMath, tier 4	4.9%	Not measured	Only Claude Opus 4.5 measured
ProofBench	36.0%	Not measured	Only Claude Opus 4.5 measured
LMArena Text: math	1463	1408	Claude Opus 4.5
LMArena Text: mathematical work	1468	1412	Claude Opus 4.5
Neither model has a result on the other 2 boards here

KnowledgeLike-for-likePublic boards, shown as published, kept out of the index101

Knowledge benchmarks for Claude Opus 4.5 and Mistral Medium 3.1
Benchmark	Claude Opus 4.5	Mistral Medium 3.1	Leader
MMLU Pro	87.3%	75.3%	Claude Opus 4.5
LegalBench (Vals AI)	84.6%	62.0%	Claude Opus 4.5
CaseLaw (Vals AI)	62.6%	Not measured	Only Claude Opus 4.5 measured
CorpFin (Vals AI)	65.1%	50.7%	Claude Opus 4.5
TaxEval (Vals AI)	74.9%	70.3%	Claude Opus 4.5
MortgageTax (Vals AI)	68.7%	36.5%	Claude Opus 4.5
MedQA (Vals AI)	95.9%	78.2%	Claude Opus 4.5
MedCode (Vals AI)	49.2%	Not measured	Only Claude Opus 4.5 measured
MMLU Pro (Artificial Analysis run)	89.5%	68.3%	Claude Opus 4.5
SimpleQA Verified	45.7%	Not measured	Only Claude Opus 4.5 measured
GeoBench	75.0%	Not measured	Only Claude Opus 4.5 measured
LMArena Text: science	1454	1444	Claude Opus 4.5
LMArena Text: medicine and healthcare	1444	1449	Mistral Medium 3.1
LMArena Text: legal and government	1459	1439	Claude Opus 4.5
LMArena Text: business and finance	1448	1418	Claude Opus 4.5
FACTS Benchmark Suite	43.9%	Not measured	Only Claude Opus 4.5 measured
Neither model has a result on the other 2 boards here

Web designLike-for-likePublic boards, shown as published, kept out of the index80

Web design benchmarks for Claude Opus 4.5 and Mistral Medium 3.1
Benchmark	Claude Opus 4.5	Mistral Medium 3.1	Leader
Design Arena: websites	1247	1133	Claude Opus 4.5
Design Arena: UI components	1238	1100	Claude Opus 4.5
Design Arena: game dev	1229	1074	Claude Opus 4.5
Design Arena: data viz	1243	1144	Claude Opus 4.5
Design Arena: 3D	1214	1081	Claude Opus 4.5
Design Arena: all code categories	1242	1120	Claude Opus 4.5
Design Arena: SVG	1181	993	Claude Opus 4.5
Design Arena: ASCII art	1190	997	Claude Opus 4.5
Neither model has a result on the other 1 board here

GeneralLike-for-likePublic boards, shown as published, kept out of the index210

General benchmarks for Claude Opus 4.5 and Mistral Medium 3.1
Benchmark	Claude Opus 4.5	Mistral Medium 3.1	Leader
SAGE (Vals AI)	52.1%	Not measured	Only Claude Opus 4.5 measured
MedScribe (Vals AI)	85.3%	Not measured	Only Claude Opus 4.5 measured
IFBench	58.0%	39.8%	Claude Opus 4.5
Long context reasoning (AA-LCR)	77.3%	42.7%	Claude Opus 4.5
DTBench	89.9%	67.5%	Claude Opus 4.5
LMCA	44.5%	19.1%	Claude Opus 4.5
CL-bench	21.1%	Not measured	Only Claude Opus 4.5 measured
Furniture assembly	28.3%	Not measured	Only Claude Opus 4.5 measured
LMArena Text	1451	1424	Claude Opus 4.5
LMArena Text: instruction following	1478	1398	Claude Opus 4.5
LMArena Text: creative writing	1445	1391	Claude Opus 4.5
LMArena Vision	Not measured	1172	Only Mistral Medium 3.1 measured
LMArena Text: English	1461	1438	Claude Opus 4.5
LMArena Text: non-English	1438	1408	Claude Opus 4.5
LMArena Text: Chinese	1470	1447	Claude Opus 4.5
LMArena Text: German	1449	1432	Claude Opus 4.5
LMArena Text: Japanese	1417	1379	Claude Opus 4.5
LMArena Text: Korean	1424	1380	Claude Opus 4.5
LMArena Text: French	1471	1460	Claude Opus 4.5
LMArena Text: Spanish	1457	1433	Claude Opus 4.5
LMArena Text: Russian	1447	1411	Claude Opus 4.5
LMArena Text: Polish	1439	1430	Claude Opus 4.5
LMArena Text: multi-turn	1466	1418	Claude Opus 4.5
LMArena Text: longer queries	1479	1406	Claude Opus 4.5
LMArena Text: writing and language	1452	1395	Claude Opus 4.5
LMArena Text: entertainment and media	1434	1390	Claude Opus 4.5
LMArena Vision: English	Not measured	1179	Only Mistral Medium 3.1 measured
LMArena Vision: Chinese	Not measured	1190	Only Mistral Medium 3.1 measured
LMArena Vision: reading text	Not measured	1175	Only Mistral Medium 3.1 measured
LMArena Vision: humor	Not measured	1168	Only Mistral Medium 3.1 measured
LMArena Vision: captioning	Not measured	1145	Only Mistral Medium 3.1 measured
LMArena Vision: recognizing things	Not measured	1147	Only Mistral Medium 3.1 measured
LMArena Vision: creative writing	Not measured	1200	Only Mistral Medium 3.1 measured
LMArena Document	1462	Not measured	Only Claude Opus 4.5 measured
Neither model has a result on the other 12 boards here

Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared

Image generation benchmarks for Claude Opus 4.5 and Mistral Medium 3.1
Benchmark	Claude Opus 4.5	Mistral Medium 3.1	Leader
Neither model has a result on 5 boards here

What each workload costs

Three fixed token mixes at each model's listed price, so per-token rates become a bill.

Chat turn

1K input + 500 output tokens

Claude Opus 4.5$0.018Fits in one request

Mistral Medium 3.1$0.0014Fits in one request

Mistral Medium 3.1 costs less

Repository review

50K input + 3K output tokens

Claude Opus 4.5$0.325Fits in one request

Mistral Medium 3.1$0.026Fits in one request

Mistral Medium 3.1 costs less

Agent loop

200K input + 10K output tokens

Claude Opus 4.5$1.25Exceeds the context window

Mistral Medium 3.1$0.100Exceeds the context window

Mistral Medium 3.1 costs less

Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.

Specification differences

The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.

Specifications of Claude Opus 4.5 and Mistral Medium 3.1
Specification	Anthropic Claude Opus 4.5	Mistral Medium 3.1
Maker	Anthropic	Mistral AI
Weights	No public weights listed	No public weights listed
Released	November 24, 2025	August 13, 2025
Context window	200K	131K
Input $/Mtok	$5.00	$0.40
Output $/Mtok	$25.00	$2.00
Coding index	44.0	Not benchmarked
Independent measurements behind it	3	0
Cost per solved task	$1.37	Not computable
Source	OpenRouter listing	OpenRouter listing

Questions

Is Claude Opus 4.5 better than Mistral Medium 3.1 for coding?

Only Claude Opus 4.5 has a coding score, 44.0 on the Vibe Coding Index; Mistral Medium 3.1 has none, so the two cannot be ranked on coding. Pick Mistral Medium 3.1 for output tokens 12.5x cheaper ($2.00 vs $25.00 per million) and work measured by LMArena Text: medicine and healthcare, where it leads.

Which is cheaper, Claude Opus 4.5 or Mistral Medium 3.1?

Claude Opus 4.5 costs $5.00 per million input tokens and $25.00 per million output tokens; Mistral Medium 3.1 costs $0.40 and $2.00. Cost per solved task is known for Claude Opus 4.5 only.

Which has the bigger context window, Claude Opus 4.5 or Mistral Medium 3.1?

Claude Opus 4.5, with 200K tokens against 131K.

How many benchmarks is the Claude Opus 4.5 vs Mistral Medium 3.1 comparison based on?

59 benchmarks have a result for both models as of October 21, 2026. Claude Opus 4.5's coding index rests on 3 independent benchmarks and Mistral Medium 3.1's on 0. Where only one model has a result, the page says so instead of naming a winner.

Claude Opus 4.5 or Mistral Medium 3.1: which to pick

Which one for your work

Coding

Intelligence

Agentic work

Reasoning

Math

Knowledge

Web design

Long documents

Everyday cost

Cost per solved task

At a glance

Benchmark by benchmark

What each workload costs

Chat turn

Repository review

Agent loop

Specification differences

Questions

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