Gemini 3.1 Flash Lite vs GLM 5.1
Gemini 3.1 Flash Lite costs 2.9x less per output token than GLM 5.1 ($1.50 vs $4.40 per million). Updated October 21, 2026; 12 benchmarks have a result for both.
Gemini 3.1 Flash Lite or GLM 5.1: which to pick
Only GLM 5.1 has a coding score, 49.2 on the Vibe Coding Index; Gemini 3.1 Flash Lite has none, so the two cannot be ranked on coding.
Pick Gemini 3.1 Flash Lite for output tokens 2.9x cheaper ($1.50 vs $4.40 per million) and a larger context window (1.05M against 205K tokens).
- Shared results
- 12
- Gemini 3.1 Flash Lite only
- 4
- GLM 5.1 only
- 77
- 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
No call
Only GLM 5.1 has a coding score, so no call is made.
One side not measured
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
No call
Only GLM 5.1 has a GPQA Diamond result, 84.5%.
Directional only
Math
AIME
No call
Only GLM 5.1 has a AIME result, 91.9%.
Directional only
Knowledge
MMLU Pro
No call
Only GLM 5.1 has a MMLU Pro result, 86.9%.
Directional only
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
Gemini 3.1 Flash Lite
Gemini 3.1 Flash Lite takes 1.05M tokens against 205K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Gemini 3.1 Flash Lite
Gemini 3.1 Flash Lite $0.0010, GLM 5.1 $0.0036 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only GLM 5.1 has the number, $0.60.
Directional only
At a glance
- Coding index
- Gemini 3.1 Flash Lite not benchmarked, GLM 5.1 49.2 from 3 benchmarks.
- Widest category
- Agentic work, 66.4 points apart on average over 1 shared benchmark.
- Widest single gap
- τ²-Bench Telecom: Gemini 3.1 Flash Lite 31.3% against GLM 5.1 97.7%, 66.4 points apart on a 0 to 100 scale.
- Output price
- Gemini 3.1 Flash Lite $1.50 against GLM 5.1 $4.40 per million output tokens, 2.9x apart.
- Context window
- Gemini 3.1 Flash Lite takes 1.05M tokens, GLM 5.1 205K.
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.
| Category | Gemini 3.1 Flash Lite | Bars | GLM 5.1 | Ties |
|---|---|---|---|---|
| Coding | 0 | 3 | ||
| Intelligence | 0 | 1 | ||
| Agentic work | 0 | 1 | ||
| Reasoning | 0 | 3 | ||
| Math | 0 | 2 | ||
| General | 2 | 0 | ||
| All shared boards | 2 | 10 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index03
| Benchmark | Gemini 3.1 Flash Lite | GLM 5.1 | Leader |
|---|---|---|---|
| LMArena WebDev | Not measured | 1508 | Only GLM 5.1 measured |
| AA Coding Index | Not measured | 55.8 | Only GLM 5.1 measured |
| LiveCodeBench (Vals AI) | Not measured | 81.4% | Only GLM 5.1 measured |
| SWE-bench Verified (Vals AI) | Not measured | 76.4% | Only GLM 5.1 measured |
| Vibe Code Bench (Vals AI) | Not measured | 31.5% | Only GLM 5.1 measured |
| Code migration (Vals AI) | Not measured | 25.8% | Only GLM 5.1 measured |
| ProgramBench (Vals AI) | Not measured | 0.0% | Only GLM 5.1 measured |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 56.9% | Only GLM 5.1 measured |
| SciCode | 43.4% | 44.8% | GLM 5.1 |
| Terminal-Bench Hard (Artificial Analysis run) | 24.2% | 43.2% | GLM 5.1 |
| WeirdML | 52.2% | 57.1% | GLM 5.1 |
| ALE-Bench | Not measured | 887.1 | Only GLM 5.1 measured |
| LMArena Text: coding | Not measured | 1485 | Only GLM 5.1 measured |
| LMArena Text: software and IT | Not measured | 1484 | Only GLM 5.1 measured |
| LMArena WebDev: React | Not measured | 1505 | Only GLM 5.1 measured |
| LMArena WebDev: HTML | Not measured | 1508 | 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 index01
| Benchmark | Gemini 3.1 Flash Lite | GLM 5.1 | Leader |
|---|---|---|---|
| AA Intelligence Index | Not measured | 26.1 | Only GLM 5.1 measured |
| Epoch Capabilities Index | 144.3 | 149.8 | GLM 5.1 |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Gemini 3.1 Flash Lite | GLM 5.1 | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 23.9 | Only GLM 5.1 measured |
| Design Arena: agents building web apps | Not measured | 1175 | Only GLM 5.1 measured |
| Design Arena: agents building full-stack apps | Not measured | 1167 | Only GLM 5.1 measured |
| Design Arena: agents building mobile apps | Not measured | 1162 | Only GLM 5.1 measured |
| Design Arena: agents building Android apps | Not measured | 1180 | Only GLM 5.1 measured |
| Design Arena: agents building Godot games | Not measured | 1053 | Only GLM 5.1 measured |
| Design Arena: agents building games | Not measured | 1164 | Only GLM 5.1 measured |
| Design Arena: HTML slides | Not measured | 1170 | Only GLM 5.1 measured |
| Design Arena: PowerPoint slides | Not measured | 1188 | Only GLM 5.1 measured |
| Design Arena: spreadsheets | Not measured | 1315 | Only GLM 5.1 measured |
| Finance Agent (Vals AI) | Not measured | 44.8% | Only GLM 5.1 measured |
| Legal Research Bench (Vals AI) | Not measured | 27.9% | Only GLM 5.1 measured |
| τ²-Bench Telecom | 31.3% | 97.7% | GLM 5.1 |
| APEX-Agents | Not measured | 40.9% | Only GLM 5.1 measured |
| DeepResearch Bench | 37.3% | Not measured | Only Gemini 3.1 Flash Lite measured |
| Vending-Bench 2 | Not measured | $5,634 | Only GLM 5.1 measured |
| Neither model has a result on the other 25 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index03
| Benchmark | Gemini 3.1 Flash Lite | GLM 5.1 | Leader |
|---|---|---|---|
| GPQA Diamond | Not measured | 84.5% | Only GLM 5.1 measured |
| GPQA Diamond (Artificial Analysis run) | 82.2% | 86.8% | GLM 5.1 |
| Humanity's Last Exam (Artificial Analysis run) | 17.2% | 30.1% | GLM 5.1 |
| GPQA Diamond (Epoch AI run) | 81.8% | 89.9% | GLM 5.1 |
| SimpleBench | Not measured | 55.1% | Only GLM 5.1 measured |
| Chess puzzles | Not measured | 20.0% | Only GLM 5.1 measured |
| LMArena Text: hard prompts | Not measured | 1473 | Only GLM 5.1 measured |
| LMArena Text: expert | Not measured | 1478 | Only GLM 5.1 measured |
| LMArena Text: hard prompts in English | Not measured | 1482 | Only GLM 5.1 measured |
| Kagi LLM Benchmark | 67.2% | Not measured | Only Gemini 3.1 Flash Lite measured |
| Neither model has a result on the other 12 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | Gemini 3.1 Flash Lite | GLM 5.1 | Leader |
|---|---|---|---|
| AIME | Not measured | 91.9% | Only GLM 5.1 measured |
| OTIS Mock AIME | 80.0% | 93.3% | GLM 5.1 |
| FrontierMath, tiers 1 to 3 | 27.7% | 36.8% | GLM 5.1 |
| ProofBench | Not measured | 22.2% | Only GLM 5.1 measured |
| LMArena Text: math | Not measured | 1473 | Only GLM 5.1 measured |
| LMArena Text: mathematical work | Not measured | 1470 | Only GLM 5.1 measured |
| Neither model has a result on the other 7 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index11 boards, none shared
| Benchmark | Gemini 3.1 Flash Lite | GLM 5.1 | Leader |
|---|---|---|---|
| MMLU Pro | Not measured | 86.9% | Only GLM 5.1 measured |
| LegalBench (Vals AI) | Not measured | 84.4% | Only GLM 5.1 measured |
| CaseLaw (Vals AI) | Not measured | 51.5% | Only GLM 5.1 measured |
| CorpFin (Vals AI) | Not measured | 64.5% | Only GLM 5.1 measured |
| TaxEval (Vals AI) | Not measured | 71.2% | Only GLM 5.1 measured |
| MedCode (Vals AI) | Not measured | 41.6% | Only GLM 5.1 measured |
| SimpleQA Verified | Not measured | 34.0% | Only GLM 5.1 measured |
| LMArena Text: science | Not measured | 1478 | Only GLM 5.1 measured |
| LMArena Text: medicine and healthcare | Not measured | 1474 | Only GLM 5.1 measured |
| LMArena Text: legal and government | Not measured | 1465 | Only GLM 5.1 measured |
| LMArena Text: business and finance | Not measured | 1452 | Only GLM 5.1 measured |
| Neither model has a result on the other 7 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index8 boards, none shared
| Benchmark | Gemini 3.1 Flash Lite | GLM 5.1 | Leader |
|---|---|---|---|
| Design Arena: websites | Not measured | 1290 | Only GLM 5.1 measured |
| Design Arena: UI components | Not measured | 1292 | Only GLM 5.1 measured |
| Design Arena: game dev | Not measured | 1265 | Only GLM 5.1 measured |
| Design Arena: data viz | Not measured | 1366 | Only GLM 5.1 measured |
| Design Arena: 3D | Not measured | 1336 | Only GLM 5.1 measured |
| Design Arena: all code categories | Not measured | 1268 | Only GLM 5.1 measured |
| Design Arena: SVG | Not measured | 1218 | Only GLM 5.1 measured |
| Design Arena: ASCII art | Not measured | 1142 | Only GLM 5.1 measured |
| Neither model has a result on the other 1 board here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Gemini 3.1 Flash Lite | GLM 5.1 | Leader |
|---|---|---|---|
| Public Benefits Bench (Vals AI) | Not measured | 61.8% | Only GLM 5.1 measured |
| MedScribe (Vals AI) | Not measured | 72.3% | Only GLM 5.1 measured |
| IFBench | 77.2% | 76.3% | Gemini 3.1 Flash Lite |
| Long context reasoning (AA-LCR) | 74.3% | 73.7% | Gemini 3.1 Flash Lite |
| DTBench | 76.8% | Not measured | Only Gemini 3.1 Flash Lite measured |
| LMCA | 35.0% | Not measured | Only Gemini 3.1 Flash Lite measured |
| ExploitBench | Not measured | 18.1% | Only GLM 5.1 measured |
| LMArena Text | Not measured | 1463 | Only GLM 5.1 measured |
| LMArena Text: instruction following | Not measured | 1453 | Only GLM 5.1 measured |
| LMArena Text: creative writing | Not measured | 1453 | Only GLM 5.1 measured |
| LMArena Text: English | Not measured | 1476 | Only GLM 5.1 measured |
| LMArena Text: non-English | Not measured | 1448 | Only GLM 5.1 measured |
| LMArena Text: Chinese | Not measured | 1515 | Only GLM 5.1 measured |
| LMArena Text: German | Not measured | 1467 | Only GLM 5.1 measured |
| LMArena Text: Japanese | Not measured | 1435 | Only GLM 5.1 measured |
| LMArena Text: Korean | Not measured | 1424 | Only GLM 5.1 measured |
| LMArena Text: French | Not measured | 1470 | Only GLM 5.1 measured |
| LMArena Text: Spanish | Not measured | 1468 | Only GLM 5.1 measured |
| LMArena Text: Russian | Not measured | 1454 | Only GLM 5.1 measured |
| LMArena Text: Polish | Not measured | 1449 | Only GLM 5.1 measured |
| LMArena Text: multi-turn | Not measured | 1473 | Only GLM 5.1 measured |
| LMArena Text: longer queries | Not measured | 1467 | Only GLM 5.1 measured |
| LMArena Text: writing and language | Not measured | 1454 | Only GLM 5.1 measured |
| LMArena Text: entertainment and media | Not measured | 1442 | Only GLM 5.1 measured |
| Neither model has a result on the other 22 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Gemini 3.1 Flash Lite | GLM 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
Gemini 3.1 Flash Lite costs less
Repository review
50K input + 3K output tokens
Gemini 3.1 Flash Lite costs less
Agent loop
200K input + 10K output tokens
Gemini 3.1 Flash Lite 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.
| Specification | Google Gemini 3.1 Flash Lite | Z.ai GLM 5.1 |
|---|---|---|
| Maker | Z.ai | |
| Weights | No public weights listed | Open weights |
| Released | May 7, 2026 | April 7, 2026 |
| Context window | 1.05M | 205K |
| Input $/Mtok | $0.25 | $1.40 |
| Output $/Mtok | $1.50 | $4.40 |
| Coding index | Not benchmarked | 49.2 |
| Independent measurements behind it | 0 | 3 |
| Cost per solved task | Not computable | $0.60 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Gemini 3.1 Flash Lite better than GLM 5.1 for coding?
Only GLM 5.1 has a coding score, 49.2 on the Vibe Coding Index; Gemini 3.1 Flash Lite has none, so the two cannot be ranked on coding. Pick Gemini 3.1 Flash Lite for output tokens 2.9x cheaper ($1.50 vs $4.40 per million) and a larger context window (1.05M against 205K tokens).
Which is cheaper, Gemini 3.1 Flash Lite or GLM 5.1?
Gemini 3.1 Flash Lite costs $0.25 per million input tokens and $1.50 per million output tokens; GLM 5.1 costs $1.40 and $4.40. Cost per solved task is known for GLM 5.1 only.
Which has the bigger context window, Gemini 3.1 Flash Lite or GLM 5.1?
Gemini 3.1 Flash Lite, with 1.05M tokens against 205K.
How many benchmarks is the Gemini 3.1 Flash Lite vs GLM 5.1 comparison based on?
12 benchmarks have a result for both models as of October 21, 2026. Gemini 3.1 Flash Lite's coding index rests on 0 independent benchmarks and GLM 5.1's on 3. Where only one model has a result, the page says so instead of naming a winner.