GLM 5.1 vs GPT-5.1

GLM 5.1 leads GPT-5.1 on coding, 49.2 to 40.4 on the Vibe Coding Index, and GLM 5.1 costs 2.3x less per output token ($4.40 vs $10.00 per million). Updated October 22, 2026; 67 benchmarks have a result for both.

Replace GLM 5.1 Replace GPT-5.1

GLM 5.1Z.ai

Coding: 49.2
Overall: 57.5
Output $/M: $4.40

GPT-5.1OpenAI

Coding: 40.4
Overall: 55.0
Output $/M: $10.00

vs boards won of 67 shared

GLM 5.1 or GPT-5.1: which to pick

Pick GLM 5.1 for coding: it scores 49.2 on the Vibe Coding Index against 40.4 for GPT-5.1.

Pick GPT-5.1 for a larger context window (400K against 205K tokens) and work measured by LiveCodeBench (Vals AI) or Terminal-Bench Hard (Artificial Analysis run), where it leads.

Model AGLM 5.1Z.ai49.2/1003 independent benchmarks$0.60 per solved task Model BGPT-5.1OpenAI40.4/1003 independent benchmarks$1.02 per solved task

672234

Shared results: 67
GLM 5.1 only: 22
GPT-5.1 only: 34
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
GLM 5.1
GLM 5.1 scores 49.2 against 40.4.
3 benchmarks behind each score
Intelligence
AA Intelligence Index
GLM 5.1
GLM 5.1 leads, 26.1 against 24.7.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only GLM 5.1 has a AA Agentic Index result, 23.9.
Directional only
Reasoning
GPQA Diamond
GPT-5.1
GPT-5.1 leads, 86.6% against 84.5%.
Same board, both measured
Math
AIME
GPT-5.1
GPT-5.1 leads, 93.3% against 91.9%.
Same board, both measured
Knowledge
MMLU Pro
GLM 5.1
GLM 5.1 leads, 86.9% against 86.4%.
Same board, both measured
Web design
Design Arena: websites
GLM 5.1
GLM 5.1 leads, 1290 against 1187.
Same board, both measured
Long documents
Listed context window
GPT-5.1
GPT-5.1 takes 400K tokens against 205K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
GLM 5.1
GLM 5.1 $0.0036, GPT-5.1 $0.0063 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
GLM 5.1
GLM 5.1 $0.60, GPT-5.1 $1.02.
Published attempt cost and pass rate

At a glance

Coding index: GLM 5.1 49.2 from 3 benchmarks, GPT-5.1 40.4 from 3 benchmarks.
Widest category: Agentic work, 20.9 points apart on average over 2 shared benchmarks.
Widest single gap: Design Arena: 3D: GLM 5.1 1336 against GPT-5.1 1060, 34.5 points apart on a 0 to 100 scale.
Output price: GLM 5.1 $4.40 against GPT-5.1 $10.00 per million output tokens, 2.3x apart.
Context window: GLM 5.1 takes 205K tokens, GPT-5.1 400K.

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	GLM 5.1	GPT-5.1
Coding	8	3
Intelligence	2	0
Agentic work	2	0
Reasoning	6	3
Math	3	1
Knowledge	6	5
Web design	8	0
General	17	3
All shared boards	52	15

CodingLike-for-likeSix of these boards feed the Vibe Coding Index83

Coding benchmarks for GLM 5.1 and GPT-5.1
Benchmark	GLM 5.1	GPT-5.1	Leader
SWE-bench Verified	Not measured	66.0%	Only GPT-5.1 measured
LMArena WebDev	1508	1396	GLM 5.1
AA Coding Index	55.8	49.4	GLM 5.1
LiveCodeBench (Vals AI)	81.4%	86.5%	GPT-5.1
SWE-bench Verified (Vals AI)	76.4%	69.8%	GLM 5.1
Vibe Code Bench (Vals AI)	31.5%	24.6%	GLM 5.1
Code migration (Vals AI)	25.8%	Not measured	Only GLM 5.1 measured
ProgramBench (Vals AI)	0.0%	Not measured	Only GLM 5.1 measured
Terminal-Bench 2.1 (Vals AI)	56.9%	Not measured	Only GLM 5.1 measured
LiveCodeBench (Artificial Analysis run)	Not measured	86.8%	Only GPT-5.1 measured
SciCode	44.8%	Not measured	Only GLM 5.1 measured
Terminal-Bench Hard (Artificial Analysis run)	43.2%	45.5%	GPT-5.1
Terminal-Bench	Not measured	47.6%	Only GPT-5.1 measured
GSO-Bench	Not measured	13.7%	Only GPT-5.1 measured
WeirdML	57.1%	60.8%	GPT-5.1
ALE-Bench	887.1	Not measured	Only GLM 5.1 measured
LMArena Text: coding	1485	1453	GLM 5.1
LMArena Text: software and IT	1484	1454	GLM 5.1
LMArena WebDev: React	1505	1307	GLM 5.1
LMArena WebDev: HTML	1508	1405	GLM 5.1
LMArena WebDev: from an image	Not measured	1421	Only GPT-5.1 measured
Neither model has a result on the other 18 boards here

IntelligenceLike-for-likePublic boards, shown as published, kept out of the index20

Intelligence benchmarks for GLM 5.1 and GPT-5.1
Benchmark	GLM 5.1	GPT-5.1	Leader
AA Intelligence Index	26.1	24.7	GLM 5.1
Epoch Capabilities Index	149.8	149.8	GLM 5.1

Agentic workLike-for-likePublic boards, shown as published, kept out of the index20

Agentic work benchmarks for GLM 5.1 and GPT-5.1
Benchmark	GLM 5.1	GPT-5.1	Leader
AA Agentic Index	23.9	Not measured	Only GLM 5.1 measured
Design Arena: agents building web apps	1175	Not measured	Only GLM 5.1 measured
Design Arena: agents building full-stack apps	1167	Not measured	Only GLM 5.1 measured
Design Arena: agents building mobile apps	1162	Not measured	Only GLM 5.1 measured
Design Arena: agents building Android apps	1182	Not measured	Only GLM 5.1 measured
Design Arena: agents building Godot games	1053	Not measured	Only GLM 5.1 measured
Design Arena: agents building games	1164	Not measured	Only GLM 5.1 measured
Design Arena: HTML slides	1120	Not measured	Only GLM 5.1 measured
Design Arena: PowerPoint slides	1163	Not measured	Only GLM 5.1 measured
Design Arena: spreadsheets	1315	Not measured	Only GLM 5.1 measured
Finance Agent (Vals AI)	44.8%	Not measured	Only GLM 5.1 measured
Legal Research Bench (Vals AI)	27.9%	Not measured	Only GLM 5.1 measured
τ²-Bench Telecom	97.7%	81.9%	GLM 5.1
APEX-Agents	40.9%	Not measured	Only GLM 5.1 measured
DeepResearch Bench	Not measured	42.8%	Only GPT-5.1 measured
Vending-Bench 2	$5,634	$1,473	GLM 5.1
Neither model has a result on the other 25 boards here

ReasoningLike-for-likePublic boards, shown as published, kept out of the index63

Reasoning benchmarks for GLM 5.1 and GPT-5.1
Benchmark	GLM 5.1	GPT-5.1	Leader
GPQA Diamond	84.5%	86.6%	GPT-5.1
MMMU Pro (Vals AI)	Not measured	83.2%	Only GPT-5.1 measured
GPQA Diamond (Artificial Analysis run)	86.8%	87.3%	GPT-5.1
Humanity's Last Exam (Artificial Analysis run)	30.1%	28.5%	GLM 5.1
GPQA Diamond (Epoch AI run)	89.9%	87.6%	GLM 5.1
ARC-AGI	Not measured	72.8%	Only GPT-5.1 measured
ARC-AGI-2	Not measured	17.6%	Only GPT-5.1 measured
SimpleBench	55.1%	53.2%	GLM 5.1
Chess puzzles	20.0%	42.0%	GPT-5.1
Mystery game puzzles	Not measured	19.0%	Only GPT-5.1 measured
VPCT	Not measured	58.7%	Only GPT-5.1 measured
LMArena Text: hard prompts	1473	1457	GLM 5.1
LMArena Text: expert	1478	1470	GLM 5.1
LMArena Text: hard prompts in English	1482	1462	GLM 5.1
LMArena Vision: diagrams	Not measured	1264	Only GPT-5.1 measured
LMArena Vision: homework	Not measured	1272	Only GPT-5.1 measured
Neither model has a result on the other 6 boards here

MathLike-for-likePublic boards, shown as published, kept out of the index31

Math benchmarks for GLM 5.1 and GPT-5.1
Benchmark	GLM 5.1	GPT-5.1	Leader
AIME	91.9%	93.3%	GPT-5.1
MGSM (Vals AI)	Not measured	93.0%	Only GPT-5.1 measured
AA Math Index	Not measured	94.0	Only GPT-5.1 measured
AIME 2025 (Artificial Analysis run)	Not measured	94.0%	Only GPT-5.1 measured
OTIS Mock AIME	93.3%	88.6%	GLM 5.1
FrontierMath, tiers 1 to 3	36.8%	Not measured	Only GLM 5.1 measured
ProofBench	22.2%	Not measured	Only GLM 5.1 measured
LMArena Text: math	1473	1446	GLM 5.1
LMArena Text: mathematical work	1470	1449	GLM 5.1
Neither model has a result on the other 4 boards here

KnowledgeLike-for-likePublic boards, shown as published, kept out of the index65

Knowledge benchmarks for GLM 5.1 and GPT-5.1
Benchmark	GLM 5.1	GPT-5.1	Leader
MMLU Pro	86.9%	86.4%	GLM 5.1
LegalBench (Vals AI)	84.4%	85.7%	GPT-5.1
CaseLaw (Vals AI)	51.5%	73.4%	GPT-5.1
CorpFin (Vals AI)	64.5%	63.8%	GLM 5.1
TaxEval (Vals AI)	71.2%	74.9%	GPT-5.1
MortgageTax (Vals AI)	Not measured	61.4%	Only GPT-5.1 measured
MedQA (Vals AI)	Not measured	96.4%	Only GPT-5.1 measured
MedCode (Vals AI)	41.6%	52.7%	GPT-5.1
MMLU Pro (Artificial Analysis run)	Not measured	87.0%	Only GPT-5.1 measured
SimpleQA Verified	34.0%	48.0%	GPT-5.1
LMArena Text: science	1478	1459	GLM 5.1
LMArena Text: medicine and healthcare	1474	1456	GLM 5.1
LMArena Text: legal and government	1465	1459	GLM 5.1
LMArena Text: business and finance	1452	1431	GLM 5.1
FACTS Benchmark Suite	Not measured	45.0%	Only GPT-5.1 measured
Neither model has a result on the other 3 boards here

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

Web design benchmarks for GLM 5.1 and GPT-5.1
Benchmark	GLM 5.1	GPT-5.1	Leader
Design Arena: websites	1290	1187	GLM 5.1
Design Arena: UI components	1292	1163	GLM 5.1
Design Arena: game dev	1265	1178	GLM 5.1
Design Arena: data viz	1366	1204	GLM 5.1
Design Arena: 3D	1336	1060	GLM 5.1
Design Arena: all code categories	1268	1170	GLM 5.1
Design Arena: SVG	1218	1149	GLM 5.1
Design Arena: ASCII art	1141	1119	GLM 5.1
Neither model has a result on the other 1 board here

GeneralLike-for-likePublic boards, shown as published, kept out of the index173

General benchmarks for GLM 5.1 and GPT-5.1
Benchmark	GLM 5.1	GPT-5.1	Leader
Public Benefits Bench (Vals AI)	61.8%	Not measured	Only GLM 5.1 measured
SAGE (Vals AI)	Not measured	43.2%	Only GPT-5.1 measured
MedScribe (Vals AI)	72.3%	88.1%	GPT-5.1
IFBench	76.3%	72.9%	GLM 5.1
Long context reasoning (AA-LCR)	73.7%	80.0%	GPT-5.1
DTBench	Not measured	90.1%	Only GPT-5.1 measured
LMCA	Not measured	43.9%	Only GPT-5.1 measured
CL-bench	Not measured	23.7%	Only GPT-5.1 measured
ExploitBench	18.1%	Not measured	Only GLM 5.1 measured
CL-bench Life	Not measured	17.3%	Only GPT-5.1 measured
LMArena Text	1463	1443	GLM 5.1
LMArena Text: instruction following	1453	1443	GLM 5.1
LMArena Text: creative writing	1453	1427	GLM 5.1
LMArena Vision	Not measured	1250	Only GPT-5.1 measured
LMArena Text: English	1476	1451	GLM 5.1
LMArena Text: non-English	1448	1431	GLM 5.1
LMArena Text: Chinese	1515	1495	GLM 5.1
LMArena Text: German	1467	1438	GLM 5.1
LMArena Text: Japanese	1435	1453	GPT-5.1
LMArena Text: Korean	1424	1401	GLM 5.1
LMArena Text: French	1470	1450	GLM 5.1
LMArena Text: Spanish	1468	1433	GLM 5.1
LMArena Text: Russian	1454	1435	GLM 5.1
LMArena Text: Polish	1449	1440	GLM 5.1
LMArena Text: multi-turn	1473	1450	GLM 5.1
LMArena Text: longer queries	1467	1448	GLM 5.1
LMArena Text: writing and language	1454	1428	GLM 5.1
LMArena Text: entertainment and media	1442	1415	GLM 5.1
LMArena Vision: English	Not measured	1252	Only GPT-5.1 measured
LMArena Vision: Chinese	Not measured	1270	Only GPT-5.1 measured
LMArena Vision: reading text	Not measured	1255	Only GPT-5.1 measured
LMArena Vision: humor	Not measured	1263	Only GPT-5.1 measured
LMArena Vision: captioning	Not measured	1252	Only GPT-5.1 measured
LMArena Vision: recognizing things	Not measured	1232	Only GPT-5.1 measured
LMArena Vision: creative writing	Not measured	1266	Only GPT-5.1 measured
LMArena Document	Not measured	1403	Only GPT-5.1 measured
Neither model has a result on the other 10 boards here

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

Image generation benchmarks for GLM 5.1 and GPT-5.1
Benchmark	GLM 5.1	GPT-5.1	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

GLM 5.1$0.0036Fits in one request

GPT-5.1$0.0063Fits in one request

GLM 5.1 costs less

Repository review

50K input + 3K output tokens

GLM 5.1$0.083Fits in one request

GPT-5.1$0.092Fits in one request

GLM 5.1 costs less

Agent loop

200K input + 10K output tokens

GLM 5.1$0.324Exceeds the context window

GPT-5.1$0.350Fits in one request

GLM 5.1 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 GLM 5.1 and GPT-5.1
Specification	Z.ai GLM 5.1	OpenAI GPT-5.1
Maker	Z.ai	OpenAI
Weights	Open weights	No public weights listed
Released	April 7, 2026	November 13, 2025
Context window	205K	400K
Input $/Mtok	$1.40	$1.25
Output $/Mtok	$4.40	$10.00
Coding index	49.2	40.4
Independent measurements behind it	3	3
Cost per solved task	$0.60	$1.02
Source	OpenRouter listing	OpenRouter listing

Questions

Is GLM 5.1 better than GPT-5.1 for coding?

Pick GLM 5.1 for coding: it scores 49.2 on the Vibe Coding Index against 40.4 for GPT-5.1. Pick GPT-5.1 for a larger context window (400K against 205K tokens) and work measured by LiveCodeBench (Vals AI) or Terminal-Bench Hard (Artificial Analysis run), where it leads.

Which is cheaper, GLM 5.1 or GPT-5.1?

GLM 5.1 costs $1.40 per million input tokens and $4.40 per million output tokens; GPT-5.1 costs $1.25 and $10.00. Per solved SWE-bench Verified task, GLM 5.1 costs $0.60 and GPT-5.1 $1.02.

Which has the bigger context window, GLM 5.1 or GPT-5.1?

GPT-5.1, with 400K tokens against 205K.

How many benchmarks is the GLM 5.1 vs GPT-5.1 comparison based on?

67 benchmarks have a result for both models as of October 22, 2026. GLM 5.1's coding index rests on 3 independent benchmarks and GPT-5.1's on 3. Where only one model has a result, the page says so instead of naming a winner.

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GLM 5.1 or GPT-5.1: 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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