Claude Fable 5.1 vs Gemini 3.1 Flash Lite Preview

Claude Fable 5.1 leads Gemini 3.1 Flash Lite Preview on coding, 84.2 to 22.7 on the Vibe Coding Index, and Gemini 3.1 Flash Lite Preview costs 33.3x less per output token ($1.50 vs $50.00 per million). Updated October 22, 2026; 70 benchmarks have a result for both.

Replace Claude Fable 5.1 Replace Gemini 3.1 Flash Lite Preview

Claude Fable 5.1Anthropic

Coding: 84.2
Overall: 84.7
Output $/M: $50.00

Gemini 3.1 Flash Lite PreviewGoogle

Coding: 22.7
Overall: 36.6
Output $/M: $1.50

vs boards won of 70 shared

Claude Fable 5.1 or Gemini 3.1 Flash Lite Preview: which to pick

Pick Claude Fable 5.1 for coding: it scores 84.2 on the Vibe Coding Index against 22.7 for Gemini 3.1 Flash Lite Preview.

Pick Gemini 3.1 Flash Lite Preview for output tokens 33.3x cheaper ($1.50 vs $50.00 per million) and a larger context window (1.05M against 1M tokens).

Model AClaude Fable 5.1Anthropic84.2/1005 independent benchmarksNo cost per solved task Model BGemini 3.1 Flash Lite PreviewGoogle22.7/1003 independent benchmarks$0.18 per solved task

70549

Shared results: 70
Claude Fable 5.1 only: 54
Gemini 3.1 Flash Lite Preview only: 9
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
Claude Fable 5.1
Claude Fable 5.1 scores 84.2 against 22.7.
5 and 3 benchmarks behind the scores
Intelligence
AA Intelligence Index
Claude Fable 5.1
Claude Fable 5.1 leads, 53.4 against 15.6.
Same board, both measured
Agentic work
AA Agentic Index
Claude Fable 5.1
Claude Fable 5.1 leads, 57.9 against 1.6.
Same board, both measured
Reasoning
GPQA Diamond
Claude Fable 5.1
Claude Fable 5.1 leads, 93.4% against 81.1%.
Same board, both measured
Math
AIME
No call
Only Gemini 3.1 Flash Lite Preview has a AIME result, 83.3%.
Directional only
Knowledge
MMLU Pro
Claude Fable 5.1
Claude Fable 5.1 leads, 92.4% against 86.2%.
Same board, both measured
Web design
Design Arena: websites
Claude Fable 5.1
Claude Fable 5.1 leads, 1312 against 1082.
Same board, both measured
Long documents
Listed context window
Gemini 3.1 Flash Lite Preview
Gemini 3.1 Flash Lite Preview takes 1.05M tokens against 1M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Gemini 3.1 Flash Lite Preview
Claude Fable 5.1 $0.035, Gemini 3.1 Flash Lite Preview $0.0010 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Gemini 3.1 Flash Lite Preview has the number, $0.18.
Directional only

At a glance

Coding index: Claude Fable 5.1 84.2 from 5 benchmarks, Gemini 3.1 Flash Lite Preview 22.7 from 3 benchmarks.
Widest category: Agentic work, 50.2 points apart on average over 5 shared benchmarks.
Widest single gap: Vibe Code Bench (Vals AI): Claude Fable 5.1 90.3% against Gemini 3.1 Flash Lite Preview 0.0%, 90.3 points apart on a 0 to 100 scale.
Output price: Claude Fable 5.1 $50.00 against Gemini 3.1 Flash Lite Preview $1.50 per million output tokens, 33.3x apart.
Context window: Claude Fable 5.1 takes 1M tokens, Gemini 3.1 Flash Lite Preview 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	Claude Fable 5.1	Gemini 3.1 Flash Lite Preview
Coding	13	0
Intelligence	1	0
Agentic work	5	0
Reasoning	7	0
Math	2	0
Knowledge	9	0
Web design	8	0
General	24	1
All shared boards	69	1

CodingLike-for-likeSix of these boards feed the Vibe Coding Index130

Coding benchmarks for Claude Fable 5.1 and Gemini 3.1 Flash Lite Preview
Benchmark	Claude Fable 5.1	Gemini 3.1 Flash Lite Preview	Leader
LiveBench coding	97.7%	Not measured	Only Claude Fable 5.1 measured
LMArena WebDev	1743	1257	Claude Fable 5.1
AA Coding Index	81.6	34.7	Claude Fable 5.1
LiveCodeBench (Vals AI)	90.5%	80.1%	Claude Fable 5.1
SWE-bench Verified (Vals AI)	Not measured	62.8%	Only Gemini 3.1 Flash Lite Preview measured
Terminal-Bench 4 (Vals AI)	58.1%	Not measured	Only Claude Fable 5.1 measured
Vibe Code Bench (Vals AI)	90.3%	0.0%	Claude Fable 5.1
Code migration (Vals AI)	54.6%	4.6%	Claude Fable 5.1
ProgramBench (Vals AI)	7.0%	0.0%	Claude Fable 5.1
IOI (Vals AI)	90.8%	Not measured	Only Claude Fable 5.1 measured
Terminal-Bench 2.1 (Vals AI)	85.0%	34.1%	Claude Fable 5.1
SWE-bench Multimodal (Vals AI)	61.3%	Not measured	Only Claude Fable 5.1 measured
Vibe Code Bench 1-100 (Vals AI)	28.0%	Not measured	Only Claude Fable 5.1 measured
SkillsBench (Vals AI)	61.5%	Not measured	Only Claude Fable 5.1 measured
CyberBench (Vals AI)	70.4%	Not measured	Only Claude Fable 5.1 measured
SciCode	63.1%	Not measured	Only Claude Fable 5.1 measured
FrontierCode	50.9%	Not measured	Only Claude Fable 5.1 measured
FrontierSWE	56.3%	Not measured	Only Claude Fable 5.1 measured
GSO-Bench	88.2%	Not measured	Only Claude Fable 5.1 measured
WeirdML	92.9%	Not measured	Only Claude Fable 5.1 measured
MirrorCode	73.3%	Not measured	Only Claude Fable 5.1 measured
ALE-Bench	2143.2	797.7	Claude Fable 5.1
LMArena Text: coding	1532	1400	Claude Fable 5.1
LMArena Text: software and IT	1530	1413	Claude Fable 5.1
LMArena WebDev: React	1792	1245	Claude Fable 5.1
LMArena WebDev: HTML	1684	1276	Claude Fable 5.1
LMArena WebDev: from an image	1722	1336	Claude Fable 5.1
SciCode	Not measured	4.6%	Only Gemini 3.1 Flash Lite Preview measured
Neither model has a result on the other 11 boards here

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

Intelligence benchmarks for Claude Fable 5.1 and Gemini 3.1 Flash Lite Preview
Benchmark	Claude Fable 5.1	Gemini 3.1 Flash Lite Preview	Leader
AA Intelligence Index	53.4	15.6	Claude Fable 5.1
Epoch Capabilities Index	166.5	Not measured	Only Claude Fable 5.1 measured

Agentic workLike-for-likePublic boards, shown as published, kept out of the index50

Agentic work benchmarks for Claude Fable 5.1 and Gemini 3.1 Flash Lite Preview
Benchmark	Claude Fable 5.1	Gemini 3.1 Flash Lite Preview	Leader
AA Agentic Index	57.9	1.6	Claude Fable 5.1
Design Arena: agents building web apps	1318	Not measured	Only Claude Fable 5.1 measured
Design Arena: agents building full-stack apps	1326	Not measured	Only Claude Fable 5.1 measured
Design Arena: agents building mobile apps	1267	Not measured	Only Claude Fable 5.1 measured
Design Arena: agents building Godot games	1327	Not measured	Only Claude Fable 5.1 measured
Design Arena: PowerPoint slides	1305	Not measured	Only Claude Fable 5.1 measured
Design Arena: spreadsheets	1380	Not measured	Only Claude Fable 5.1 measured
LiveBench research	82.0%	Not measured	Only Claude Fable 5.1 measured
LiveBench browser	100.0%	Not measured	Only Claude Fable 5.1 measured
LiveBench long agentic	80.8%	Not measured	Only Claude Fable 5.1 measured
SREBench (Vals AI)	22.9%	Not measured	Only Claude Fable 5.1 measured
Finance Agent (Vals AI)	58.9%	30.0%	Claude Fable 5.1
Tax Agent Bench (Vals AI)	49.2%	3.1%	Claude Fable 5.1
Legal Research Bench (Vals AI)	55.3%	3.4%	Claude Fable 5.1
Excel Modeling Benchmark (Vals AI)	76.7%	8.6%	Claude Fable 5.1
Terminal-Bench-Science (Vals AI)	40.0%	Not measured	Only Claude Fable 5.1 measured
Time Horizon Index (Vals AI)	63.3%	Not measured	Only Claude Fable 5.1 measured
CUA-bench (Vals AI)	13.2%	Not measured	Only Claude Fable 5.1 measured
Robo-bench (Vals AI)	5.8%	Not measured	Only Claude Fable 5.1 measured
APEX-Agents	68.6%	Not measured	Only Claude Fable 5.1 measured
Remote Labor Index	17.9%	Not measured	Only Claude Fable 5.1 measured
SpireClimb	2.0%	Not measured	Only Claude Fable 5.1 measured
Vending-Bench 2	$5,422	Not measured	Only Claude Fable 5.1 measured
LMArena Search	1246	Not measured	Only Claude Fable 5.1 measured
Neither model has a result on the other 17 boards here

ReasoningLike-for-likePublic boards, shown as published, kept out of the index70

Reasoning benchmarks for Claude Fable 5.1 and Gemini 3.1 Flash Lite Preview
Benchmark	Claude Fable 5.1	Gemini 3.1 Flash Lite Preview	Leader
GPQA Diamond	93.4%	81.1%	Claude Fable 5.1
LiveBench reasoning	91.7%	Not measured	Only Claude Fable 5.1 measured
MysteryMechanism (Vals AI)	47.8%	Not measured	Only Claude Fable 5.1 measured
MMMU Pro (Vals AI)	90.6%	82.5%	Claude Fable 5.1
GPQA Diamond (Artificial Analysis run)	93.7%	Not measured	Only Claude Fable 5.1 measured
Humanity's Last Exam (Artificial Analysis run)	59.1%	Not measured	Only Claude Fable 5.1 measured
ARC-AGI	97.5%	Not measured	Only Claude Fable 5.1 measured
ARC-AGI-2	90.0%	Not measured	Only Claude Fable 5.1 measured
Chess puzzles	48.0%	Not measured	Only Claude Fable 5.1 measured
Mystery game puzzles	58.0%	Not measured	Only Claude Fable 5.1 measured
EBR-bench	57.1%	Not measured	Only Claude Fable 5.1 measured
LMArena Text: hard prompts	1528	1407	Claude Fable 5.1
LMArena Text: expert	1544	1398	Claude Fable 5.1
LMArena Text: hard prompts in English	1522	1403	Claude Fable 5.1
LMArena Vision: diagrams	1343	1242	Claude Fable 5.1
LMArena Vision: homework	1345	1271	Claude Fable 5.1
Neither model has a result on the other 6 boards here

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

Math benchmarks for Claude Fable 5.1 and Gemini 3.1 Flash Lite Preview
Benchmark	Claude Fable 5.1	Gemini 3.1 Flash Lite Preview	Leader
AIME	Not measured	83.3%	Only Gemini 3.1 Flash Lite Preview measured
OTIS Mock AIME	100.0%	Not measured	Only Claude Fable 5.1 measured
FrontierMath, tiers 1 to 3	90.2%	Not measured	Only Claude Fable 5.1 measured
FrontierMath, tier 4	87.8%	Not measured	Only Claude Fable 5.1 measured
ProofBench	100.0%	Not measured	Only Claude Fable 5.1 measured
LMArena Text: math	1531	1428	Claude Fable 5.1
LMArena Text: mathematical work	1541	1417	Claude Fable 5.1
Neither model has a result on the other 6 boards here

KnowledgeLike-for-likePublic boards, shown as published, kept out of the index90

Knowledge benchmarks for Claude Fable 5.1 and Gemini 3.1 Flash Lite Preview
Benchmark	Claude Fable 5.1	Gemini 3.1 Flash Lite Preview	Leader
MMLU Pro	92.4%	86.2%	Claude Fable 5.1
LegalBench (Vals AI)	88.5%	83.8%	Claude Fable 5.1
CaseLaw (Vals AI)	Not measured	55.0%	Only Gemini 3.1 Flash Lite Preview measured
CorpFin (Vals AI)	Not measured	59.4%	Only Gemini 3.1 Flash Lite Preview measured
TaxEval (Vals AI)	76.0%	71.8%	Claude Fable 5.1
MortgageTax (Vals AI)	70.8%	68.0%	Claude Fable 5.1
MedCode (Vals AI)	53.5%	47.6%	Claude Fable 5.1
SimpleQA Verified	70.8%	Not measured	Only Claude Fable 5.1 measured
LMArena Text: science	1532	1425	Claude Fable 5.1
LMArena Text: medicine and healthcare	1531	1428	Claude Fable 5.1
LMArena Text: legal and government	1514	1418	Claude Fable 5.1
LMArena Text: business and finance	1493	1389	Claude Fable 5.1
FACTS Benchmark Suite	Not measured	51.4%	Only Gemini 3.1 Flash Lite Preview measured
Neither model has a result on the other 5 boards here

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

Web design benchmarks for Claude Fable 5.1 and Gemini 3.1 Flash Lite Preview
Benchmark	Claude Fable 5.1	Gemini 3.1 Flash Lite Preview	Leader
Design Arena: websites	1312	1082	Claude Fable 5.1
Design Arena: UI components	1336	1069	Claude Fable 5.1
Design Arena: game dev	1381	1029	Claude Fable 5.1
Design Arena: data viz	1344	1045	Claude Fable 5.1
Design Arena: 3D	1392	1047	Claude Fable 5.1
Design Arena: all code categories	1335	1072	Claude Fable 5.1
Design Arena: SVG	1300	1052	Claude Fable 5.1
Design Arena: ASCII art	1323	1167	Claude Fable 5.1
LiveBench design	83.4%	Not measured	Only Claude Fable 5.1 measured

GeneralLike-for-likePublic boards, shown as published, kept out of the index241

General benchmarks for Claude Fable 5.1 and Gemini 3.1 Flash Lite Preview
Benchmark	Claude Fable 5.1	Gemini 3.1 Flash Lite Preview	Leader
LiveBench data analysis	80.3%	Not measured	Only Claude Fable 5.1 measured
Public Benefits Bench (Vals AI)	74.9%	Not measured	Only Claude Fable 5.1 measured
SAGE (Vals AI)	48.5%	49.5%	Gemini 3.1 Flash Lite Preview
MedScribe (Vals AI)	91.3%	63.9%	Claude Fable 5.1
Vals Multimodal Index	Not measured	41.4%	Only Gemini 3.1 Flash Lite Preview measured
Long context reasoning (AA-LCR)	85.3%	Not measured	Only Claude Fable 5.1 measured
DTBench	97.6%	Not measured	Only Claude Fable 5.1 measured
LMCA	65.5%	Not measured	Only Claude Fable 5.1 measured
Furniture assembly	70.0%	Not measured	Only Claude Fable 5.1 measured
LMArena Text	1512	1416	Claude Fable 5.1
LMArena Text: instruction following	1518	1377	Claude Fable 5.1
LMArena Text: creative writing	1509	1401	Claude Fable 5.1
LMArena Vision	1319	1240	Claude Fable 5.1
LMArena Text: English	1506	1414	Claude Fable 5.1
LMArena Text: non-English	1508	1410	Claude Fable 5.1
LMArena Text: Chinese	1584	1460	Claude Fable 5.1
LMArena Text: German	1499	1430	Claude Fable 5.1
LMArena Text: Japanese	1562	1413	Claude Fable 5.1
LMArena Text: Korean	1517	1392	Claude Fable 5.1
LMArena Text: French	1523	1424	Claude Fable 5.1
LMArena Text: Spanish	1520	1421	Claude Fable 5.1
LMArena Text: Russian	1520	1420	Claude Fable 5.1
LMArena Text: Polish	1525	1443	Claude Fable 5.1
LMArena Text: multi-turn	1493	1417	Claude Fable 5.1
LMArena Text: longer queries	1524	1394	Claude Fable 5.1
LMArena Text: writing and language	1510	1408	Claude Fable 5.1
LMArena Text: entertainment and media	1497	1386	Claude Fable 5.1
LMArena Vision: English	1313	1232	Claude Fable 5.1
LMArena Vision: Chinese	1391	1278	Claude Fable 5.1
LMArena Vision: reading text	1327	1246	Claude Fable 5.1
LMArena Vision: humor	1318	1266	Claude Fable 5.1
LMArena Vision: captioning	Not measured	1259	Only Gemini 3.1 Flash Lite Preview measured
LMArena Vision: recognizing things	Not measured	1308	Only Gemini 3.1 Flash Lite Preview measured
LMArena Vision: creative writing	1330	1248	Claude Fable 5.1
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 Claude Fable 5.1 and Gemini 3.1 Flash Lite Preview
Benchmark	Claude Fable 5.1	Gemini 3.1 Flash Lite Preview	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

Claude Fable 5.1$0.035Fits in one request

Gemini 3.1 Flash Lite Preview$0.0010Fits in one request

Gemini 3.1 Flash Lite Preview costs less

Repository review

50K input + 3K output tokens

Claude Fable 5.1$0.650Fits in one request

Gemini 3.1 Flash Lite Preview$0.017Fits in one request

Gemini 3.1 Flash Lite Preview costs less

Agent loop

200K input + 10K output tokens

Claude Fable 5.1$2.50Fits in one request

Gemini 3.1 Flash Lite Preview$0.065Fits in one request

Gemini 3.1 Flash Lite Preview 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 Claude Fable 5.1 and Gemini 3.1 Flash Lite Preview
Specification	Anthropic Claude Fable 5.1	Google Gemini 3.1 Flash Lite Preview
Maker	Anthropic	Google
Weights	No public weights listed	No public weights listed
Released	September 1, 2026	March 3, 2026
Context window	1M	1.05M
Input $/Mtok	$10.00	$0.25
Output $/Mtok	$50.00	$1.50
Coding index	84.2	22.7
Independent measurements behind it	5	3
Cost per solved task	Not computable	$0.18
Source	OpenRouter listing	OpenRouter listing

Questions

Is Claude Fable 5.1 better than Gemini 3.1 Flash Lite Preview for coding?

Pick Claude Fable 5.1 for coding: it scores 84.2 on the Vibe Coding Index against 22.7 for Gemini 3.1 Flash Lite Preview. Pick Gemini 3.1 Flash Lite Preview for output tokens 33.3x cheaper ($1.50 vs $50.00 per million) and a larger context window (1.05M against 1M tokens).

Which is cheaper, Claude Fable 5.1 or Gemini 3.1 Flash Lite Preview?

Claude Fable 5.1 costs $10.00 per million input tokens and $50.00 per million output tokens; Gemini 3.1 Flash Lite Preview costs $0.25 and $1.50. Cost per solved task is known for Gemini 3.1 Flash Lite Preview only.

Which has the bigger context window, Claude Fable 5.1 or Gemini 3.1 Flash Lite Preview?

Gemini 3.1 Flash Lite Preview, with 1.05M tokens against 1M.

How many benchmarks is the Claude Fable 5.1 vs Gemini 3.1 Flash Lite Preview comparison based on?

70 benchmarks have a result for both models as of October 22, 2026. Claude Fable 5.1's coding index rests on 5 independent benchmarks and Gemini 3.1 Flash Lite Preview's on 3. Where only one model has a result, the page says so instead of naming a winner.

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Claude Fable 5.1 or Gemini 3.1 Flash Lite Preview: 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