GLM 5.1 vs Qwen3.5 Plus 2026-04-20

GLM 5.1 leads Qwen3.5 Plus 2026-04-20 on coding, 49.2 to 39.5 on the Vibe Coding Index, and Qwen3.5 Plus 2026-04-20 costs 2.4x less per output token ($1.80 vs $4.40 per million). Updated October 22, 2026; 16 benchmarks have a result for both.

Replace GLM 5.1 Replace Qwen3.5 Plus 2026-04-20

GLM 5.1Z.ai

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

Qwen3.5 Plus 2026-04-20Qwen

Coding: 39.5
Overall: No data
Output $/M: $1.80

vs boards won of 16 shared

GLM 5.1 or Qwen3.5 Plus 2026-04-20: which to pick

Pick GLM 5.1 for coding: it scores 49.2 on the Vibe Coding Index against 39.5 for Qwen3.5 Plus 2026-04-20.

Pick Qwen3.5 Plus 2026-04-20 for output tokens 2.4x cheaper ($1.80 vs $4.40 per million) and a larger context window (1M against 205K tokens).

Model AGLM 5.1Z.ai49.2/1003 independent benchmarks$0.60 per solved task Model BQwen3.5 Plus 2026-04-20Qwen39.5/1002 independent benchmarks$1.35 per solved task

16739

Shared results: 16
GLM 5.1 only: 73
Qwen3.5 Plus 2026-04-20 only: 9
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
GLM 5.1
GLM 5.1 scores 49.2 against 39.5.
3 and 2 benchmarks behind the scores
Intelligence
AA Intelligence Index
No call
Only GLM 5.1 has a AA Intelligence Index result, 26.1.
Directional only
Agentic work
AA Agentic Index
No call
Only GLM 5.1 has a AA Agentic Index result, 23.9.
Directional only
Reasoning
GPQA Diamond
Qwen3.5 Plus 2026-04-20
Qwen3.5 Plus 2026-04-20 leads, 87.4% against 84.5%.
Same board, both measured
Math
AIME
GLM 5.1
GLM 5.1 leads, 91.9% against 86.0%.
Same board, both measured
Knowledge
MMLU Pro
Qwen3.5 Plus 2026-04-20
Qwen3.5 Plus 2026-04-20 leads, 87.2% against 86.9%.
Same board, both measured
Web design
Design Arena: websites
No call
Only GLM 5.1 has a Design Arena: websites result, 1290.
Directional only
Long documents
Listed context window
Qwen3.5 Plus 2026-04-20
Qwen3.5 Plus 2026-04-20 takes 1M tokens against 205K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Qwen3.5 Plus 2026-04-20
GLM 5.1 $0.0036, Qwen3.5 Plus 2026-04-20 $0.0012 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
GLM 5.1
GLM 5.1 $0.60, Qwen3.5 Plus 2026-04-20 $1.35.
Published attempt cost and pass rate

At a glance

Coding index: GLM 5.1 49.2 from 3 benchmarks, Qwen3.5 Plus 2026-04-20 39.5 from 2 benchmarks.
Widest category: Agentic work, 35.2 points apart on average over 1 shared benchmark.
Widest single gap: Vending-Bench 2: GLM 5.1 $5,634 against Qwen3.5 Plus 2026-04-20 $1, 35.2 points apart on a 0 to 100 scale.
Output price: GLM 5.1 $4.40 against Qwen3.5 Plus 2026-04-20 $1.80 per million output tokens, 2.4x apart.
Context window: GLM 5.1 takes 205K tokens, Qwen3.5 Plus 2026-04-20 1M.

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	Qwen3.5 Plus 2026-04-20
Coding	3	1
Intelligence	1	0
Agentic work	1	0
Reasoning	2	1
Math	2	0
Knowledge	1	4
All shared boards	10	6

CodingLike-for-likeSix of these boards feed the Vibe Coding Index31

Coding benchmarks for GLM 5.1 and Qwen3.5 Plus 2026-04-20
Benchmark	GLM 5.1	Qwen3.5 Plus 2026-04-20	Leader
LMArena WebDev	1508	Not measured	Only GLM 5.1 measured
AA Coding Index	55.8	Not measured	Only GLM 5.1 measured
LiveCodeBench (Vals AI)	81.4%	85.3%	Qwen3.5 Plus 2026-04-20
SWE-bench Verified (Vals AI)	76.4%	71.2%	GLM 5.1
Vibe Code Bench (Vals AI)	31.5%	15.7%	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
SciCode	44.8%	Not measured	Only GLM 5.1 measured
Terminal-Bench Hard (Artificial Analysis run)	43.2%	Not measured	Only GLM 5.1 measured
WeirdML	57.1%	Not measured	Only GLM 5.1 measured
ALE-Bench	887.1	608.9	GLM 5.1
LMArena Text: coding	1485	Not measured	Only GLM 5.1 measured
LMArena Text: software and IT	1484	Not measured	Only GLM 5.1 measured
LMArena WebDev: React	1505	Not measured	Only GLM 5.1 measured
LMArena WebDev: HTML	1508	Not measured	Only GLM 5.1 measured
Neither model has a result on the other 23 boards here

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

Intelligence benchmarks for GLM 5.1 and Qwen3.5 Plus 2026-04-20
Benchmark	GLM 5.1	Qwen3.5 Plus 2026-04-20	Leader
AA Intelligence Index	26.1	Not measured	Only GLM 5.1 measured
Epoch Capabilities Index	149.8	146.2	GLM 5.1

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

Agentic work benchmarks for GLM 5.1 and Qwen3.5 Plus 2026-04-20
Benchmark	GLM 5.1	Qwen3.5 Plus 2026-04-20	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%	Not measured	Only GLM 5.1 measured
APEX-Agents	40.9%	Not measured	Only GLM 5.1 measured
Vending-Bench 2	$5,634	$1	GLM 5.1
Neither model has a result on the other 26 boards here

ReasoningLike-for-likePublic boards, shown as published, kept out of the index21

Reasoning benchmarks for GLM 5.1 and Qwen3.5 Plus 2026-04-20
Benchmark	GLM 5.1	Qwen3.5 Plus 2026-04-20	Leader
GPQA Diamond	84.5%	87.4%	Qwen3.5 Plus 2026-04-20
MMMU Pro (Vals AI)	Not measured	22.8%	Only Qwen3.5 Plus 2026-04-20 measured
GPQA Diamond (Artificial Analysis run)	86.8%	Not measured	Only GLM 5.1 measured
Humanity's Last Exam (Artificial Analysis run)	30.1%	Not measured	Only GLM 5.1 measured
GPQA Diamond (Epoch AI run)	89.9%	84.8%	GLM 5.1
SimpleBench	55.1%	Not measured	Only GLM 5.1 measured
Chess puzzles	20.0%	8.0%	GLM 5.1
Mystery game puzzles	Not measured	17.0%	Only Qwen3.5 Plus 2026-04-20 measured
LMArena Text: hard prompts	1473	Not measured	Only GLM 5.1 measured
LMArena Text: expert	1478	Not measured	Only GLM 5.1 measured
LMArena Text: hard prompts in English	1482	Not measured	Only GLM 5.1 measured
Neither model has a result on the other 11 boards here

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

Math benchmarks for GLM 5.1 and Qwen3.5 Plus 2026-04-20
Benchmark	GLM 5.1	Qwen3.5 Plus 2026-04-20	Leader
AIME	91.9%	86.0%	GLM 5.1
OTIS Mock AIME	93.3%	86.7%	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	Not measured	Only GLM 5.1 measured
LMArena Text: mathematical work	1470	Not measured	Only GLM 5.1 measured
Neither model has a result on the other 7 boards here

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

Knowledge benchmarks for GLM 5.1 and Qwen3.5 Plus 2026-04-20
Benchmark	GLM 5.1	Qwen3.5 Plus 2026-04-20	Leader
MMLU Pro	86.9%	87.2%	Qwen3.5 Plus 2026-04-20
LegalBench (Vals AI)	84.4%	85.1%	Qwen3.5 Plus 2026-04-20
CaseLaw (Vals AI)	51.5%	59.7%	Qwen3.5 Plus 2026-04-20
CorpFin (Vals AI)	64.5%	65.3%	Qwen3.5 Plus 2026-04-20
TaxEval (Vals AI)	71.2%	Not measured	Only GLM 5.1 measured
MortgageTax (Vals AI)	Not measured	60.8%	Only Qwen3.5 Plus 2026-04-20 measured
MedQA (Vals AI)	Not measured	95.2%	Only Qwen3.5 Plus 2026-04-20 measured
MedCode (Vals AI)	41.6%	Not measured	Only GLM 5.1 measured
SimpleQA Verified	34.0%	25.4%	GLM 5.1
LMArena Text: science	1478	Not measured	Only GLM 5.1 measured
LMArena Text: medicine and healthcare	1474	Not measured	Only GLM 5.1 measured
LMArena Text: legal and government	1465	Not measured	Only GLM 5.1 measured
LMArena Text: business and finance	1452	Not measured	Only GLM 5.1 measured
Neither model has a result on the other 5 boards here

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

Web design benchmarks for GLM 5.1 and Qwen3.5 Plus 2026-04-20
Benchmark	GLM 5.1	Qwen3.5 Plus 2026-04-20	Leader
Design Arena: websites	1290	Not measured	Only GLM 5.1 measured
Design Arena: UI components	1292	Not measured	Only GLM 5.1 measured
Design Arena: game dev	1265	Not measured	Only GLM 5.1 measured
Design Arena: data viz	1366	Not measured	Only GLM 5.1 measured
Design Arena: 3D	1336	Not measured	Only GLM 5.1 measured
Design Arena: all code categories	1268	Not measured	Only GLM 5.1 measured
Design Arena: SVG	1218	Not measured	Only GLM 5.1 measured
Design Arena: ASCII art	1141	Not measured	Only GLM 5.1 measured
Neither model has a result on the other 1 board here

GeneralDirectional onlyPublic boards, shown as published, kept out of the index27 boards, none shared

General benchmarks for GLM 5.1 and Qwen3.5 Plus 2026-04-20
Benchmark	GLM 5.1	Qwen3.5 Plus 2026-04-20	Leader
Public Benefits Bench (Vals AI)	61.8%	Not measured	Only GLM 5.1 measured
SAGE (Vals AI)	Not measured	30.4%	Only Qwen3.5 Plus 2026-04-20 measured
MedScribe (Vals AI)	72.3%	Not measured	Only GLM 5.1 measured
IFBench	76.3%	Not measured	Only GLM 5.1 measured
Long context reasoning (AA-LCR)	73.7%	Not measured	Only GLM 5.1 measured
DTBench	Not measured	80.5%	Only Qwen3.5 Plus 2026-04-20 measured
LMCA	Not measured	36.4%	Only Qwen3.5 Plus 2026-04-20 measured
CL-bench	Not measured	19.8%	Only Qwen3.5 Plus 2026-04-20 measured
ExploitBench	18.1%	Not measured	Only GLM 5.1 measured
CL-bench Life	Not measured	12.4%	Only Qwen3.5 Plus 2026-04-20 measured
LMArena Text	1463	Not measured	Only GLM 5.1 measured
LMArena Text: instruction following	1453	Not measured	Only GLM 5.1 measured
LMArena Text: creative writing	1453	Not measured	Only GLM 5.1 measured
LMArena Text: English	1476	Not measured	Only GLM 5.1 measured
LMArena Text: non-English	1448	Not measured	Only GLM 5.1 measured
LMArena Text: Chinese	1515	Not measured	Only GLM 5.1 measured
LMArena Text: German	1467	Not measured	Only GLM 5.1 measured
LMArena Text: Japanese	1435	Not measured	Only GLM 5.1 measured
LMArena Text: Korean	1424	Not measured	Only GLM 5.1 measured
LMArena Text: French	1470	Not measured	Only GLM 5.1 measured
LMArena Text: Spanish	1468	Not measured	Only GLM 5.1 measured
LMArena Text: Russian	1454	Not measured	Only GLM 5.1 measured
LMArena Text: Polish	1449	Not measured	Only GLM 5.1 measured
LMArena Text: multi-turn	1473	Not measured	Only GLM 5.1 measured
LMArena Text: longer queries	1467	Not measured	Only GLM 5.1 measured
LMArena Text: writing and language	1454	Not measured	Only GLM 5.1 measured
LMArena Text: entertainment and media	1442	Not measured	Only GLM 5.1 measured
Neither model has a result on the other 19 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 Qwen3.5 Plus 2026-04-20
Benchmark	GLM 5.1	Qwen3.5 Plus 2026-04-20	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

Qwen3.5 Plus 2026-04-20$0.0012Fits in one request

Qwen3.5 Plus 2026-04-20 costs less

Repository review

50K input + 3K output tokens

GLM 5.1$0.083Fits in one request

Qwen3.5 Plus 2026-04-20$0.020Fits in one request

Qwen3.5 Plus 2026-04-20 costs less

Agent loop

200K input + 10K output tokens

GLM 5.1$0.324Exceeds the context window

Qwen3.5 Plus 2026-04-20$0.078Fits in one request

Qwen3.5 Plus 2026-04-20 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 Qwen3.5 Plus 2026-04-20
Specification	Z.ai GLM 5.1	Qwen3.5 Plus 2026-04-20
Maker	Z.ai	Qwen
Weights	Open weights	No public weights listed
Released	April 7, 2026	April 27, 2026
Context window	205K	1M
Input $/Mtok	$1.40	$0.30
Output $/Mtok	$4.40	$1.80
Coding index	49.2	39.5
Independent measurements behind it	3	2
Cost per solved task	$0.60	$1.35
Source	OpenRouter listing	OpenRouter listing

Questions

Is GLM 5.1 better than Qwen3.5 Plus 2026-04-20 for coding?

Pick GLM 5.1 for coding: it scores 49.2 on the Vibe Coding Index against 39.5 for Qwen3.5 Plus 2026-04-20. Pick Qwen3.5 Plus 2026-04-20 for output tokens 2.4x cheaper ($1.80 vs $4.40 per million) and a larger context window (1M against 205K tokens).

Which is cheaper, GLM 5.1 or Qwen3.5 Plus 2026-04-20?

GLM 5.1 costs $1.40 per million input tokens and $4.40 per million output tokens; Qwen3.5 Plus 2026-04-20 costs $0.30 and $1.80. Per solved SWE-bench Verified task, GLM 5.1 costs $0.60 and Qwen3.5 Plus 2026-04-20 $1.35.

Which has the bigger context window, GLM 5.1 or Qwen3.5 Plus 2026-04-20?

Qwen3.5 Plus 2026-04-20, with 1M tokens against 205K.

How many benchmarks is the GLM 5.1 vs Qwen3.5 Plus 2026-04-20 comparison based on?

16 benchmarks have a result for both models as of October 22, 2026. GLM 5.1's coding index rests on 3 independent benchmarks and Qwen3.5 Plus 2026-04-20's on 2. Where only one model has a result, the page says so instead of naming a winner.

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GLM 5.1 or Qwen3.5 Plus 2026-04-20: 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

Compare next