GLM 5.3 Flash vs GPT-6.1 Terra

GPT-6.1 Terra leads GLM 5.3 Flash on coding, 77.4 to 57.7 on the Vibe Coding Index, and GLM 5.3 Flash costs 10.0x less per output token ($0.50 vs $5.00 per million). Updated October 29, 2026; 30 benchmarks have a result for both.

Replace GLM 5.3 Flash Replace GPT-6.1 Terra

GLM 5.3 FlashZ.ai

Coding: 57.7
Overall: 65.8
Output $/M: $0.50

GPT-6.1 TerraOpenAI

Coding: 77.4
Overall: 76.8
Output $/M: $5.00

vs boards won of 30 shared

GLM 5.3 Flash or GPT-6.1 Terra: which to pick

Pick GPT-6.1 Terra for coding: it scores 77.4 on the Vibe Coding Index against 57.7 for GLM 5.3 Flash, though on 4 benchmarks against 6.

Pick GLM 5.3 Flash for output tokens 10.0x cheaper ($0.50 vs $5.00 per million) and work measured by Tax Agent Bench (Vals AI) or Legal Research Bench (Vals AI), where it leads.

Model AGLM 5.3 FlashZ.ai57.7/1006 independent benchmarks$0.02 per solved task Model BGPT-6.1 TerraOpenAI77.4/1004 independent benchmarksNo cost per solved task

30726

Shared results: 30
GLM 5.3 Flash only: 72
GPT-6.1 Terra only: 6
Like-for-like categories: 6 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
GPT-6.1 Terra
GPT-6.1 Terra scores 77.4 against 57.7.
6 and 4 benchmarks behind the scores
Intelligence
AA Intelligence Index
No call
Only GPT-6.1 Terra has a AA Intelligence Index result, 51.0.
Directional only
Agentic work
AA Agentic Index
No call
Only GLM 5.3 Flash has a AA Agentic Index result, 50.9.
Directional only
Reasoning
GPQA Diamond
No call
Only GLM 5.3 Flash has a GPQA Diamond result, 86.4%.
Directional only
Knowledge
MMLU Pro
No call
Only GLM 5.3 Flash has a MMLU Pro result, 86.1%.
Directional only
Web design
Design Arena: websites
GPT-6.1 Terra
GPT-6.1 Terra leads, 1283 against 1271.
Same board, both measured
General
Vals Index
GPT-6.1 Terra
GPT-6.1 Terra leads, 60.5% against 50.9%.
Same board, both measured
Long documents
Listed context window
GPT-6.1 Terra
GPT-6.1 Terra takes 1.05M tokens against 1.05M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
GLM 5.3 Flash
GLM 5.3 Flash $0.0004, GPT-6.1 Terra $0.0035 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only GLM 5.3 Flash has the number, $0.02.
Directional only

At a glance

Coding index: GLM 5.3 Flash 57.7 from 6 benchmarks, GPT-6.1 Terra 77.4 from 4 benchmarks.
Widest category: Math, 38.9 points apart on average over 3 shared benchmarks.
Widest single gap: ALE-Bench: GLM 5.3 Flash 303.6 against GPT-6.1 Terra 2608.8, 76.8 points apart on a 0 to 100 scale.
Output price: GLM 5.3 Flash $0.50 against GPT-6.1 Terra $5.00 per million output tokens, 10.0x apart.
Context window: GLM 5.3 Flash takes 1.05M tokens, GPT-6.1 Terra 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	GLM 5.3 Flash	GPT-6.1 Terra
Coding	0	8
Agentic work	3	4
Reasoning	0	4
Math	0	3
Web design	1	4
General	0	3
All shared boards	4	26

CodingLike-for-likeSix of these boards feed the Vibe Coding Index08

Coding benchmarks for GLM 5.3 Flash and GPT-6.1 Terra
Benchmark	GLM 5.3 Flash	GPT-6.1 Terra	Leader
LiveBench coding	80.6%	94.3%	GPT-6.1 Terra
LMArena WebDev	1607	1673	GPT-6.1 Terra
AA Coding Index	71.5	Not measured	Only GLM 5.3 Flash measured
LiveCodeBench (Vals AI)	80.5%	Not measured	Only GLM 5.3 Flash measured
SWE-bench Verified (Vals AI)	92.0%	Not measured	Only GLM 5.3 Flash measured
Terminal-Bench 4 (Vals AI)	37.4%	49.5%	GPT-6.1 Terra
Vibe Code Bench (Vals AI)	30.8%	84.0%	GPT-6.1 Terra
Code migration (Vals AI)	20.5%	Not measured	Only GLM 5.3 Flash measured
ProgramBench (Vals AI)	0.0%	Not measured	Only GLM 5.3 Flash measured
IOI (Vals AI)	52.5%	Not measured	Only GLM 5.3 Flash measured
Terminal-Bench 2.1 (Vals AI)	62.9%	Not measured	Only GLM 5.3 Flash measured
Vibe Code Bench 1-100 (Vals AI)	16.0%	Not measured	Only GLM 5.3 Flash measured
SkillsBench (Vals AI)	40.2%	Not measured	Only GLM 5.3 Flash measured
CyberBench (Vals AI)	67.9%	Not measured	Only GLM 5.3 Flash measured
SciCode	51.6%	55.1%	GPT-6.1 Terra
FrontierCode	31.8%	Not measured	Only GLM 5.3 Flash measured
FrontierSWE	18.1%	Not measured	Only GLM 5.3 Flash measured
ALE-Bench	303.6	2608.8	GPT-6.1 Terra
LMArena Text: coding	1509	Not measured	Only GLM 5.3 Flash measured
LMArena Text: software and IT	1502	Not measured	Only GLM 5.3 Flash measured
LMArena WebDev: React	1624	1657	GPT-6.1 Terra
LMArena WebDev: HTML	1577	1719	GPT-6.1 Terra
LMArena WebDev: from an image	1578	Not measured	Only GLM 5.3 Flash measured
Neither model has a result on the other 20 boards here

IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared

Intelligence benchmarks for GLM 5.3 Flash and GPT-6.1 Terra
Benchmark	GLM 5.3 Flash	GPT-6.1 Terra	Leader
AA Intelligence Index	Not measured	51.0	Only GPT-6.1 Terra measured
Epoch Capabilities Index	153.1	Not measured	Only GLM 5.3 Flash measured

Agentic workLike-for-likePublic boards, shown as published, kept out of the index34

Agentic work benchmarks for GLM 5.3 Flash and GPT-6.1 Terra
Benchmark	GLM 5.3 Flash	GPT-6.1 Terra	Leader
AA Agentic Index	50.9	Not measured	Only GLM 5.3 Flash measured
LiveBench research	70.1%	73.9%	GPT-6.1 Terra
LiveBench browser	59.8%	93.1%	GPT-6.1 Terra
LiveBench long agentic	19.0%	48.6%	GPT-6.1 Terra
SREBench (Vals AI)	0.8%	Not measured	Only GLM 5.3 Flash measured
Finance Agent (Vals AI)	57.9%	Not measured	Only GLM 5.3 Flash measured
Tax Agent Bench (Vals AI)	31.6%	15.2%	GLM 5.3 Flash
Legal Research Bench (Vals AI)	45.2%	26.0%	GLM 5.3 Flash
Harvey's Legal Agent Benchmark (Vals AI)	10.4%	1.7%	GLM 5.3 Flash
Excel Modeling Benchmark (Vals AI)	55.9%	Not measured	Only GLM 5.3 Flash measured
Terminal-Bench-Science (Vals AI)	2.9%	Not measured	Only GLM 5.3 Flash measured
APEX-Agents	52.8%	68.3%	GPT-6.1 Terra
Neither model has a result on the other 30 boards here

ReasoningLike-for-likePublic boards, shown as published, kept out of the index04

Reasoning benchmarks for GLM 5.3 Flash and GPT-6.1 Terra
Benchmark	GLM 5.3 Flash	GPT-6.1 Terra	Leader
GPQA Diamond	86.4%	Not measured	Only GLM 5.3 Flash measured
LiveBench reasoning	77.6%	88.7%	GPT-6.1 Terra
MMMU Pro (Vals AI)	86.0%	Not measured	Only GLM 5.3 Flash measured
GPQA Diamond (Artificial Analysis run)	91.2%	Not measured	Only GLM 5.3 Flash measured
Humanity's Last Exam (Artificial Analysis run)	39.9%	46.2%	GPT-6.1 Terra
GPQA Diamond (Epoch AI run)	90.2%	94.3%	GPT-6.1 Terra
ARC-AGI	91.0%	Not measured	Only GLM 5.3 Flash measured
ARC-AGI-2	65.8%	Not measured	Only GLM 5.3 Flash measured
Chess puzzles	21.0%	Not measured	Only GLM 5.3 Flash measured
Mystery game puzzles	8.0%	74.0%	GPT-6.1 Terra
EBR-bench	Not measured	78.1%	Only GPT-6.1 Terra measured
LMArena Text: hard prompts	1492	Not measured	Only GLM 5.3 Flash measured
LMArena Text: expert	1514	Not measured	Only GLM 5.3 Flash measured
LMArena Text: hard prompts in English	1489	Not measured	Only GLM 5.3 Flash measured
LMArena Vision: diagrams	1317	Not measured	Only GLM 5.3 Flash measured
LMArena Vision: homework	1318	Not measured	Only GLM 5.3 Flash measured
Humanity's Last Exam (Scale run)	Not measured	35.7%	Only GPT-6.1 Terra measured
Neither model has a result on the other 6 boards here

MathLike-for-likePublic boards, shown as published, kept out of the index03

Math benchmarks for GLM 5.3 Flash and GPT-6.1 Terra
Benchmark	GLM 5.3 Flash	GPT-6.1 Terra	Leader
OTIS Mock AIME	93.9%	100.0%	GPT-6.1 Terra
FrontierMath, tiers 1 to 3	55.8%	90.9%	GPT-6.1 Terra
FrontierMath, tier 4	17.1%	92.7%	GPT-6.1 Terra
ProofBench	21.0%	Not measured	Only GLM 5.3 Flash measured
LMArena Text: math	1502	Not measured	Only GLM 5.3 Flash measured
LMArena Text: mathematical work	1496	Not measured	Only GLM 5.3 Flash measured
Neither model has a result on the other 8 boards here

KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index8 boards, none shared

Knowledge benchmarks for GLM 5.3 Flash and GPT-6.1 Terra
Benchmark	GLM 5.3 Flash	GPT-6.1 Terra	Leader
MMLU Pro	86.1%	Not measured	Only GLM 5.3 Flash measured
LegalBench (Vals AI)	83.9%	Not measured	Only GLM 5.3 Flash measured
TaxEval (Vals AI)	75.6%	Not measured	Only GLM 5.3 Flash measured
SimpleQA Verified	Not measured	57.3%	Only GPT-6.1 Terra measured
LMArena Text: science	1484	Not measured	Only GLM 5.3 Flash measured
LMArena Text: medicine and healthcare	1478	Not measured	Only GLM 5.3 Flash measured
LMArena Text: legal and government	1475	Not measured	Only GLM 5.3 Flash measured
LMArena Text: business and finance	1461	Not measured	Only GLM 5.3 Flash measured
Neither model has a result on the other 12 boards here

Web designLike-for-likePublic boards, shown as published, kept out of the index14

Web design benchmarks for GLM 5.3 Flash and GPT-6.1 Terra
Benchmark	GLM 5.3 Flash	GPT-6.1 Terra	Leader
Design Arena: websites	1271	1283	GPT-6.1 Terra
Design Arena: UI components	1308	1277	GLM 5.3 Flash
Design Arena: game dev	1275	1348	GPT-6.1 Terra
Design Arena: data viz	1260	Not measured	Only GLM 5.3 Flash measured
Design Arena: 3D	1314	Not measured	Only GLM 5.3 Flash measured
Design Arena: all code categories	1279	1295	GPT-6.1 Terra
Design Arena: SVG	1281	Not measured	Only GLM 5.3 Flash measured
Design Arena: ASCII art	1270	Not measured	Only GLM 5.3 Flash measured
LiveBench design	77.2%	82.3%	GPT-6.1 Terra

GeneralLike-for-likePublic boards, shown as published, kept out of the index03

General benchmarks for GLM 5.3 Flash and GPT-6.1 Terra
Benchmark	GLM 5.3 Flash	GPT-6.1 Terra	Leader
Vals Index	50.9%	60.5%	GPT-6.1 Terra
LiveBench data analysis	76.4%	82.3%	GPT-6.1 Terra
SAGE (Vals AI)	89.3%	Not measured	Only GLM 5.3 Flash measured
MedScribe (Vals AI)	88.9%	Not measured	Only GLM 5.3 Flash measured
Long context reasoning (AA-LCR)	80.0%	82.7%	GPT-6.1 Terra
Surface Evolver Bench	52.5%	Not measured	Only GLM 5.3 Flash measured
Furniture assembly	Not measured	79.2%	Only GPT-6.1 Terra measured
LMArena Text	1473	Not measured	Only GLM 5.3 Flash measured
LMArena Text: instruction following	1481	Not measured	Only GLM 5.3 Flash measured
LMArena Text: creative writing	1441	Not measured	Only GLM 5.3 Flash measured
LMArena Vision	1294	Not measured	Only GLM 5.3 Flash measured
LMArena Text: English	1475	Not measured	Only GLM 5.3 Flash measured
LMArena Text: non-English	1463	Not measured	Only GLM 5.3 Flash measured
LMArena Text: Chinese	1530	Not measured	Only GLM 5.3 Flash measured
LMArena Text: German	1455	Not measured	Only GLM 5.3 Flash measured
LMArena Text: Japanese	1450	Not measured	Only GLM 5.3 Flash measured
LMArena Text: Korean	1442	Not measured	Only GLM 5.3 Flash measured
LMArena Text: French	1488	Not measured	Only GLM 5.3 Flash measured
LMArena Text: Spanish	1473	Not measured	Only GLM 5.3 Flash measured
LMArena Text: Russian	1467	Not measured	Only GLM 5.3 Flash measured
LMArena Text: Polish	1452	Not measured	Only GLM 5.3 Flash measured
LMArena Text: multi-turn	1471	Not measured	Only GLM 5.3 Flash measured
LMArena Text: longer queries	1484	Not measured	Only GLM 5.3 Flash measured
LMArena Text: writing and language	1456	Not measured	Only GLM 5.3 Flash measured
LMArena Text: entertainment and media	1442	Not measured	Only GLM 5.3 Flash measured
LMArena Vision: English	1295	Not measured	Only GLM 5.3 Flash measured
LMArena Vision: Chinese	1363	Not measured	Only GLM 5.3 Flash measured
LMArena Vision: reading text	1299	Not measured	Only GLM 5.3 Flash measured
LMArena Vision: humor	1279	Not measured	Only GLM 5.3 Flash measured
LMArena Vision: creative writing	1270	Not measured	Only GLM 5.3 Flash measured
MultiChallenge	Not measured	74.2%	Only GPT-6.1 Terra measured
Neither model has a result on the other 17 boards here

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

Image generation benchmarks for GLM 5.3 Flash and GPT-6.1 Terra
Benchmark	GLM 5.3 Flash	GPT-6.1 Terra	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 5.3 Flash$0.0004Fits in one request

GPT-6.1 Terra$0.0035Fits in one request

GLM 5.3 Flash costs less

Repository review

50K input + 3K output tokens

GLM 5.3 Flash$0.0090Fits in one request

GPT-6.1 Terra$0.065Fits in one request

GLM 5.3 Flash costs less

Agent loop

200K input + 10K output tokens

GLM 5.3 Flash$0.035Fits in one request

GPT-6.1 Terra$0.250Fits in one request

GLM 5.3 Flash 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 5.3 Flash and GPT-6.1 Terra
Specification	Z.ai GLM 5.3 Flash	OpenAI GPT-6.1 Terra
Maker	Z.ai	OpenAI
Weights	Open weights	No public weights listed
Released	August 26, 2026	October 26, 2026
Context window	1.05M	1.05M
Input $/Mtok	$0.15	$1.00
Output $/Mtok	$0.50	$5.00
Coding index	57.7	77.4
Independent measurements behind it	6	4
Cost per solved task	$0.02	Not computable
Source	OpenRouter listing	OpenRouter listing

Questions

Is GLM 5.3 Flash better than GPT-6.1 Terra for coding?

Pick GPT-6.1 Terra for coding: it scores 77.4 on the Vibe Coding Index against 57.7 for GLM 5.3 Flash, though on 4 benchmarks against 6. Pick GLM 5.3 Flash for output tokens 10.0x cheaper ($0.50 vs $5.00 per million) and work measured by Tax Agent Bench (Vals AI) or Legal Research Bench (Vals AI), where it leads.

Which is cheaper, GLM 5.3 Flash or GPT-6.1 Terra?

GLM 5.3 Flash costs $0.15 per million input tokens and $0.50 per million output tokens; GPT-6.1 Terra costs $1.00 and $5.00. Cost per solved task is known for GLM 5.3 Flash only.

Which has the bigger context window, GLM 5.3 Flash or GPT-6.1 Terra?

GPT-6.1 Terra, with 1.05M tokens against 1.05M.

How many benchmarks is the GLM 5.3 Flash vs GPT-6.1 Terra comparison based on?

30 benchmarks have a result for both models as of October 29, 2026. GLM 5.3 Flash's coding index rests on 6 independent benchmarks and GPT-6.1 Terra's on 4. Where only one model has a result, the page says so instead of naming a winner.

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GLM 5.3 Flash or GPT-6.1 Terra: which to pick

Which one for your work

Coding

Intelligence

Agentic work

Reasoning

Knowledge

Web design

General

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

Compare next