GPT-5.6 Luna vs Mistral Large 4

Updated October 21, 2026. 79 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.

Replace GPT-5.6 Luna Replace Mistral Large 4

GPT-5.6 LunaOpenAI

Coding: 61.5
Overall: 37.3
Output $/M: $1.20

Mistral Large 4Mistral AI

Coding: 55.3
Overall: 38.4
Output $/M: $4.18

vs boards won of 79 shared, 1 tied

Decision reading

Pick GPT-5.6 Luna for coding: it scores 61.5 on the Vibe Coding Index against 55.3 for Mistral Large 4.

Pick Mistral Large 4 when what matters is LMArena WebDev or Terminal-Bench 4 (Vals AI), where it leads.

Model AGPT-5.6 LunaOpenAI61.5/1002 independent benchmarks$0.04 per solved task Model BMistral Large 4Mistral AI55.3/1002 independent benchmarksNo cost per solved task

79372

Shared results: 79
GPT-5.6 Luna only: 37
Mistral Large 4 only: 2
Like-for-like categories: 8 of 9

Shared results can support a head-to-head reading. Results only one model has describe coverage, not superiority.

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, four public coding benchmarks
GPT-5.6 Luna
GPT-5.6 Luna scores 61.5 against 55.3.
2 benchmarks behind each score
Intelligence
AA Intelligence Index
Mistral Large 4
Mistral Large 4 leads, 38.4 against 37.3.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only GPT-5.6 Luna has a AA Agentic Index result, 42.1.
Directional only
Reasoning
GPQA Diamond
No call
Only GPT-5.6 Luna has a GPQA Diamond result, 91.7%.
Directional only
Knowledge
MMLU Pro
No call
Only GPT-5.6 Luna has a MMLU Pro result, 86.0%.
Directional only
Web design
Design Arena: websites
Mistral Large 4
Mistral Large 4 leads, 1258 against 1256.
Same board, both measured
Long documents
Listed context window
GPT-5.6 Luna
GPT-5.6 Luna takes 1.05M tokens against 1.05M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
GPT-5.6 Luna
GPT-5.6 Luna $0.0008, Mistral Large 4 $0.0034 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only GPT-5.6 Luna has the number, $0.04.
Directional only

At a glance

Coding index: GPT-5.6 Luna 61.5 from 2 benchmarks, Mistral Large 4 55.3 from 2 benchmarks.
Widest category: Math, 18.4 points apart on average over 6 shared benchmarks.
Widest single gap: LiveBench browser: GPT-5.6 Luna 68.0% against Mistral Large 4 8.0%, 60.0 points apart on a 0 to 100 scale.
Output price: GPT-5.6 Luna $1.20 against Mistral Large 4 $4.18 per million output tokens, 3.5x apart.
Context window: GPT-5.6 Luna takes 1.05M tokens, Mistral Large 4 1.05M.

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	GPT-5.6 Luna	Mistral Large 4	Ties
Coding	7	7
Intelligence	1	1
Agentic work	6	2
Reasoning	9	1
Math	4	1	1 tie
Knowledge	3	3
Web design	1	8
General	14	10
All shared boards	45	33	1 tie

CodingLike-for-likeFour of these boards feed the Vibe Coding Index77

Coding benchmarks for GPT-5.6 Luna and Mistral Large 4
Benchmark	GPT-5.6 Luna	Mistral Large 4	Leader
LiveBench coding	73.6%	60.0%	GPT-5.6 Luna
LMArena WebDev	1518	1543	Mistral Large 4
AA Coding Index	71.4	Not measured	Only GPT-5.6 Luna measured
SWE-bench Verified (Vals AI)	93.0%	Not measured	Only GPT-5.6 Luna measured
Terminal-Bench 4 (Vals AI)	11.6%	27.8%	Mistral Large 4
Vibe Code Bench (Vals AI)	77.1%	78.4%	Mistral Large 4
Code migration (Vals AI)	44.5%	30.6%	GPT-5.6 Luna
ProgramBench (Vals AI)	0.0%	Not measured	Only GPT-5.6 Luna measured
IOI (Vals AI)	61.8%	45.3%	GPT-5.6 Luna
Terminal-Bench 2.1 (Vals AI)	79.0%	Not measured	Only GPT-5.6 Luna measured
SWE-bench Multimodal (Vals AI)	Not measured	33.1%	Only Mistral Large 4 measured
Vibe Code Bench 1-100 (Vals AI)	22.6%	14.3%	GPT-5.6 Luna
SkillsBench (Vals AI)	60.5%	Not measured	Only GPT-5.6 Luna measured
CyberBench (Vals AI)	73.6%	Not measured	Only GPT-5.6 Luna measured
SciCode	53.6%	54.2%	Mistral Large 4
FrontierCode	39.8%	39.4%	GPT-5.6 Luna
WeirdML	60.9%	Not measured	Only GPT-5.6 Luna measured
ALE-Bench	1667.4	1213.2	GPT-5.6 Luna
LMArena Text: coding	1466	1478	Mistral Large 4
LMArena Text: software and IT	1463	1467	Mistral Large 4
LMArena WebDev: React	1508	1559	Mistral Large 4
LMArena WebDev: HTML	1520	1487	GPT-5.6 Luna
LMArena WebDev: from an image	1517	Not measured	Only GPT-5.6 Luna measured
Neither model has a result on the other 15 boards here

IntelligenceLike-for-likePublic boards, shown as published, kept out of the index11

Intelligence benchmarks for GPT-5.6 Luna and Mistral Large 4
Benchmark	GPT-5.6 Luna	Mistral Large 4	Leader
AA Intelligence Index	37.3	38.4	Mistral Large 4
Epoch Capabilities Index	156.5	150.0	GPT-5.6 Luna

Agentic workLike-for-likePublic boards, shown as published, kept out of the index62

Agentic work benchmarks for GPT-5.6 Luna and Mistral Large 4
Benchmark	GPT-5.6 Luna	Mistral Large 4	Leader
AA Agentic Index	42.1	Not measured	Only GPT-5.6 Luna measured
LiveBench research	51.0%	28.1%	GPT-5.6 Luna
LiveBench browser	68.0%	8.0%	GPT-5.6 Luna
LiveBench long agentic	30.4%	11.8%	GPT-5.6 Luna
SREBench (Vals AI)	1.5%	Not measured	Only GPT-5.6 Luna measured
Finance Agent (Vals AI)	55.0%	54.7%	GPT-5.6 Luna
Tax Agent Bench (Vals AI)	24.8%	30.4%	Mistral Large 4
Legal Research Bench (Vals AI)	36.5%	31.7%	GPT-5.6 Luna
Harvey's Legal Agent Benchmark (Vals AI)	Not measured	17.5%	Only Mistral Large 4 measured
Excel Modeling Benchmark (Vals AI)	67.1%	56.2%	GPT-5.6 Luna
BioMysteryBench (Vals AI)	61.5%	67.0%	Mistral Large 4
Terminal-Bench-Science (Vals AI)	0.0%	Not measured	Only GPT-5.6 Luna measured
Vals Science Index	25.3%	Not measured	Only GPT-5.6 Luna measured
APEX-Agents	43.0%	Not measured	Only GPT-5.6 Luna measured
BALROG	45.6%	Not measured	Only GPT-5.6 Luna measured
Vending-Bench 2	$4,095	Not measured	Only GPT-5.6 Luna measured
Neither model has a result on the other 23 boards here

ReasoningLike-for-likePublic boards, shown as published, kept out of the index91

Reasoning benchmarks for GPT-5.6 Luna and Mistral Large 4
Benchmark	GPT-5.6 Luna	Mistral Large 4	Leader
GPQA Diamond	91.7%	Not measured	Only GPT-5.6 Luna measured
LiveBench reasoning	85.6%	83.9%	GPT-5.6 Luna
MysteryMechanism (Vals AI)	14.4%	12.2%	GPT-5.6 Luna
MMMU Pro (Vals AI)	85.0%	Not measured	Only GPT-5.6 Luna measured
GPQA Diamond (Artificial Analysis run)	91.1%	Not measured	Only GPT-5.6 Luna measured
Humanity's Last Exam (Artificial Analysis run)	39.5%	35.0%	GPT-5.6 Luna
GPQA Diamond (Epoch AI run)	91.6%	88.1%	GPT-5.6 Luna
ARC-AGI	88.0%	Not measured	Only GPT-5.6 Luna measured
ARC-AGI-2	59.5%	Not measured	Only GPT-5.6 Luna measured
SimpleBench	46.8%	Not measured	Only GPT-5.6 Luna measured
Chess puzzles	43.0%	33.0%	GPT-5.6 Luna
Mystery game puzzles	21.0%	17.0%	GPT-5.6 Luna
LMArena Text: hard prompts	1451	1444	GPT-5.6 Luna
LMArena Text: expert	1478	1444	GPT-5.6 Luna
LMArena Text: hard prompts in English	1460	1442	GPT-5.6 Luna
LMArena Vision: diagrams	1273	1288	Mistral Large 4
LMArena Vision: homework	1282	Not measured	Only GPT-5.6 Luna measured
Neither model has a result on the other 4 boards here

MathLike-for-likePublic boards, shown as published, kept out of the index41

Math benchmarks for GPT-5.6 Luna and Mistral Large 4
Benchmark	GPT-5.6 Luna	Mistral Large 4	Leader
OTIS Mock AIME	98.3%	98.3%	Tie
FrontierMath, tiers 1 to 3	82.1%	58.6%	GPT-5.6 Luna
FrontierMath, tier 4	61.0%	26.8%	GPT-5.6 Luna
ProofBench	60.0%	10.0%	GPT-5.6 Luna
LMArena Text: math	1459	1469	Mistral Large 4
LMArena Text: mathematical work	1470	1462	GPT-5.6 Luna
Neither model has a result on the other 7 boards here

KnowledgeLike-for-likePublic boards, shown as published, kept out of the index33

Knowledge benchmarks for GPT-5.6 Luna and Mistral Large 4
Benchmark	GPT-5.6 Luna	Mistral Large 4	Leader
MMLU Pro	86.0%	Not measured	Only GPT-5.6 Luna measured
LegalBench (Vals AI)	84.0%	Not measured	Only GPT-5.6 Luna measured
CorpFin (Vals AI)	64.2%	Not measured	Only GPT-5.6 Luna measured
TaxEval (Vals AI)	76.2%	Not measured	Only GPT-5.6 Luna measured
MortgageTax (Vals AI)	67.3%	Not measured	Only GPT-5.6 Luna measured
MedCode (Vals AI)	42.4%	40.7%	GPT-5.6 Luna
SimpleQA Verified	41.0%	20.0%	GPT-5.6 Luna
LMArena Text: science	1433	1448	Mistral Large 4
LMArena Text: medicine and healthcare	1399	1433	Mistral Large 4
LMArena Text: legal and government	1446	1425	GPT-5.6 Luna
LMArena Text: business and finance	1439	1439	Mistral Large 4
Neither model has a result on the other 6 boards here

Web designLike-for-likePublic boards, shown as published, kept out of the index18

Web design benchmarks for GPT-5.6 Luna and Mistral Large 4
Benchmark	GPT-5.6 Luna	Mistral Large 4	Leader
Design Arena: websites	1256	1258	Mistral Large 4
Design Arena: UI components	1250	1275	Mistral Large 4
Design Arena: game dev	1196	1226	Mistral Large 4
Design Arena: data viz	1212	1274	Mistral Large 4
Design Arena: 3D	1121	1253	Mistral Large 4
Design Arena: all code categories	1231	1259	Mistral Large 4
Design Arena: SVG	1193	1232	Mistral Large 4
Design Arena: ASCII art	1144	1203	Mistral Large 4
LiveBench design	76.0%	65.6%	GPT-5.6 Luna

GeneralLike-for-likePublic boards, shown as published, kept out of the index1410

General benchmarks for GPT-5.6 Luna and Mistral Large 4
Benchmark	GPT-5.6 Luna	Mistral Large 4	Leader
LiveBench data analysis	78.0%	76.5%	GPT-5.6 Luna
Public Benefits Bench (Vals AI)	61.2%	Not measured	Only GPT-5.6 Luna measured
SAGE (Vals AI)	44.2%	Not measured	Only GPT-5.6 Luna measured
MedScribe (Vals AI)	84.4%	80.4%	GPT-5.6 Luna
Vals Multimodal Index	69.1%	Not measured	Only GPT-5.6 Luna measured
Long context reasoning (AA-LCR)	83.7%	81.3%	GPT-5.6 Luna
DTBench	89.1%	88.2%	GPT-5.6 Luna
LMCA	48.5%	35.8%	GPT-5.6 Luna
Surface Evolver Bench	61.9%	28.1%	GPT-5.6 Luna
Furniture assembly	42.5%	20.8%	GPT-5.6 Luna
LMArena Text	1431	1431	Mistral Large 4
LMArena Text: instruction following	1437	1422	GPT-5.6 Luna
LMArena Text: creative writing	1396	1363	GPT-5.6 Luna
LMArena Vision	1257	1272	Mistral Large 4
LMArena Text: English	1441	1433	GPT-5.6 Luna
LMArena Text: non-English	1417	1422	Mistral Large 4
LMArena Text: Chinese	1470	1492	Mistral Large 4
LMArena Text: German	1455	Not measured	Only GPT-5.6 Luna measured
LMArena Text: Japanese	1415	1415	Mistral Large 4
LMArena Text: Korean	1415	Not measured	Only GPT-5.6 Luna measured
LMArena Text: French	1458	1492	Mistral Large 4
LMArena Text: Spanish	1446	1455	Mistral Large 4
LMArena Text: Russian	1427	1417	GPT-5.6 Luna
LMArena Text: Polish	1405	Not measured	Only GPT-5.6 Luna measured
LMArena Text: multi-turn	1434	1435	Mistral Large 4
LMArena Text: longer queries	1436	1428	GPT-5.6 Luna
LMArena Text: writing and language	1419	1386	GPT-5.6 Luna
LMArena Text: entertainment and media	1402	1378	GPT-5.6 Luna
LMArena Vision: English	1263	1283	Mistral Large 4
LMArena Vision: Chinese	1294	Not measured	Only GPT-5.6 Luna measured
LMArena Vision: reading text	1264	1284	Mistral Large 4
LMArena Vision: humor	1190	Not measured	Only GPT-5.6 Luna measured
LMArena Vision: creative writing	1257	Not measured	Only GPT-5.6 Luna measured
LMArena Document	1457	Not measured	Only GPT-5.6 Luna 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 GPT-5.6 Luna and Mistral Large 4
Benchmark	GPT-5.6 Luna	Mistral Large 4	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

GPT-5.6 Luna$0.0008Fits in one request

Mistral Large 4$0.0034Fits in one request

GPT-5.6 Luna costs less

Repository review

50K input + 3K output tokens

GPT-5.6 Luna$0.014Fits in one request

Mistral Large 4$0.081Fits in one request

GPT-5.6 Luna costs less

Agent loop

200K input + 10K output tokens

GPT-5.6 Luna$0.052Fits in one request

Mistral Large 4$0.314Fits in one request

GPT-5.6 Luna 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 GPT-5.6 Luna and Mistral Large 4
Specification	OpenAI GPT-5.6 Luna	Mistral Large 4
Maker	OpenAI	Mistral AI
Weights	No public weights listed	No public weights listed
Released	July 9, 2026	October 6, 2026
Context window	1.05M	1.05M
Input $/Mtok	$0.20	$1.36
Output $/Mtok	$1.20	$4.18
Coding index	61.5	55.3
Independent measurements behind it	2	2
Cost per solved task	$0.04	Not computable
Source	OpenRouter listing	OpenRouter listing

Questions

Is GPT-5.6 Luna better than Mistral Large 4 for coding?

Pick GPT-5.6 Luna for coding: it scores 61.5 on the Vibe Coding Index against 55.3 for Mistral Large 4. Pick Mistral Large 4 when what matters is LMArena WebDev or Terminal-Bench 4 (Vals AI), where it leads.

Which is cheaper, GPT-5.6 Luna or Mistral Large 4?

GPT-5.6 Luna costs $0.20 per million input tokens and $1.20 per million output tokens; Mistral Large 4 costs $1.36 and $4.18. Cost per solved task is known for GPT-5.6 Luna only.

Which has the bigger context window, GPT-5.6 Luna or Mistral Large 4?

GPT-5.6 Luna, with 1.05M tokens against 1.05M.

How many benchmarks is the GPT-5.6 Luna vs Mistral Large 4 comparison based on?

79 benchmarks have a result for both models as of October 21, 2026. GPT-5.6 Luna's coding index rests on 2 independent benchmarks and Mistral Large 4's on 2. Where only one model has a result, the page says so instead of naming a winner.

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Decision reading

Which one for your work

Coding

Intelligence

Agentic work

Reasoning

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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