Claude Fable 5.2 vs GPT-5.4
Claude Fable 5.2 leads GPT-5.4 on coding, 87.8 to 64.3 on the Vibe Coding Index, and GPT-5.4 costs 2.7x less per output token ($15.00 vs $40.00 per million). Updated November 14, 2026; 36 benchmarks have a result for both.
vs boards won of 36 shared
Claude Fable 5.2 or GPT-5.4: which to pick
Pick Claude Fable 5.2 for coding: it scores 87.8 on the Vibe Coding Index against 64.3 for GPT-5.4.
Pick GPT-5.4 for output tokens 2.7x cheaper ($15.00 vs $40.00 per million) and a larger context window (1.05M against 1M tokens).
Model AClaude Fable 5.2Anthropic87.8/1004 independent benchmarksNo cost per solved taskModel BGPT-5.4OpenAI64.3/1003 independent benchmarks$1.02 per solved task
- Shared results
- 36
- Claude Fable 5.2 only
- 32
- GPT-5.4 only
- 85
- 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 5.2
Claude Fable 5.2 scores 87.8 against 64.3.
4 and 3 benchmarks behind the scores
Intelligence
AA Intelligence Index
No call
Only Claude Fable 5.2 has a AA Intelligence Index result, 64.6.
Directional only
Reasoning
GPQA Diamond
No call
Only GPT-5.4 has a GPQA Diamond result, 91.7%.
Directional only
Math
AIME
No call
Only GPT-5.4 has a AIME result, 96.7%.
Directional only
Knowledge
MMLU Pro
No call
Only GPT-5.4 has a MMLU Pro result, 87.5%.
Directional only
Web design
Design Arena: websites
Claude Fable 5.2
Claude Fable 5.2 leads, 1351 against 1190.
Same board, both measured
General
Vals Index
No call
Only Claude Fable 5.2 has a Vals Index result, 71.3%.
Directional only
Long documents
Listed context window
GPT-5.4
GPT-5.4 takes 1.05M tokens against 1M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
GPT-5.4
Claude Fable 5.2 $0.028, GPT-5.4 $0.010 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only GPT-5.4 has the number, $1.02.
Directional only
At a glance
- Coding index
- Claude Fable 5.2 87.8 from 4 benchmarks, GPT-5.4 64.3 from 3 benchmarks.
- Widest category
- Agentic work, 36.6 points apart on average over 3 shared benchmarks.
- Widest single gap
- EBR-bench: Claude Fable 5.2 90.5% against GPT-5.4 25.4%, 65.1 points apart on a 0 to 100 scale.
- Output price
- Claude Fable 5.2 $40.00 against GPT-5.4 $15.00 per million output tokens, 2.7x apart.
- Context window
- Claude Fable 5.2 takes 1M tokens, GPT-5.4 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.
| Category | Claude Fable 5.2 | Bars | GPT-5.4 | Ties |
|---|---|---|---|---|
| Coding | 7 | 0 | ||
| Intelligence | 1 | 0 | ||
| Agentic work | 3 | 0 | ||
| Reasoning | 7 | 0 | ||
| Math | 5 | 0 | ||
| Knowledge | 3 | 0 | ||
| Web design | 5 | 0 | ||
| General | 5 | 0 | ||
| All shared boards | 36 | 0 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index70
| Benchmark | Claude Fable 5.2 | GPT-5.4 | Leader |
|---|---|---|---|
| LiveBench coding | 79.2% | Not measured | Only Claude Fable 5.2 measured |
| LMArena WebDev | 1838 | 1462 | Claude Fable 5.2 |
| AA Coding Index | Not measured | 71.1 | Only GPT-5.4 measured |
| LiveCodeBench (Vals AI) | Not measured | 84.1% | Only GPT-5.4 measured |
| SWE-bench Verified (Vals AI) | Not measured | 78.2% | Only GPT-5.4 measured |
| Terminal-Bench 4 (Vals AI) | 65.2% | Not measured | Only Claude Fable 5.2 measured |
| Vibe Code Bench (Vals AI) | 93.8% | 67.4% | Claude Fable 5.2 |
| Code migration (Vals AI) | Not measured | 35.0% | Only GPT-5.4 measured |
| ProgramBench (Vals AI) | 19.0% | 0.5% | Claude Fable 5.2 |
| SWE-bench Multimodal (Vals AI) | 62.3% | Not measured | Only Claude Fable 5.2 measured |
| SkillsBench (Vals AI) | Not measured | 51.7% | Only GPT-5.4 measured |
| SciCode | 67.7% | Not measured | Only Claude Fable 5.2 measured |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 57.6% | Only GPT-5.4 measured |
| Terminal-Bench 4.0 (Artificial Analysis run) | 61.6% | Not measured | Only Claude Fable 5.2 measured |
| FrontierCode 2.0 | 49.1% | Not measured | Only Claude Fable 5.2 measured |
| Terminal-Bench | Not measured | 81.8% | Only GPT-5.4 measured |
| FrontierSWE | 69.9% | Not measured | Only Claude Fable 5.2 measured |
| GSO-Bench | Not measured | 31.4% | Only GPT-5.4 measured |
| WeirdML | Not measured | 77.7% | Only GPT-5.4 measured |
| MirrorCode | Not measured | 23.3% | Only GPT-5.4 measured |
| ALE-Bench | 2509.8 | 1607.0 | Claude Fable 5.2 |
| LMArena Text: coding | Not measured | 1497 | Only GPT-5.4 measured |
| LMArena Text: software and IT | Not measured | 1492 | Only GPT-5.4 measured |
| LMArena WebDev: React | 1915 | 1451 | Claude Fable 5.2 |
| LMArena WebDev: HTML | 1738 | 1476 | Claude Fable 5.2 |
| LMArena WebDev: from an image | Not measured | 1441 | Only GPT-5.4 measured |
| SWE Atlas: Codebase QnA | Not measured | 40.8% | Only GPT-5.4 measured |
| SWE Atlas: Refactoring | Not measured | 44.3% | Only GPT-5.4 measured |
| SWE Atlas: Test Writing | Not measured | 44.4% | Only GPT-5.4 measured |
| GameBench 2 | 99.1 | 62.1 | Claude Fable 5.2 |
| CursorBench 4.0 | 60.0% | Not measured | Only Claude Fable 5.2 measured |
| ProgramBench | Not measured | 0.0% | Only GPT-5.4 measured |
| Neither model has a result on the other 20 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Claude Fable 5.2 | GPT-5.4 | Leader |
|---|---|---|---|
| AA Intelligence Index | 64.6 | Not measured | Only Claude Fable 5.2 measured |
| Epoch Capabilities Index | 173.4 | 157.8 | Claude Fable 5.2 |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index30
| Benchmark | Claude Fable 5.2 | GPT-5.4 | Leader |
|---|---|---|---|
| Design Arena: agents building web apps | Not measured | 1035 | Only GPT-5.4 measured |
| Design Arena: agents building full-stack apps | 1402 | 991 | Claude Fable 5.2 |
| Design Arena: agents building mobile apps | 1325 | 1079 | Claude Fable 5.2 |
| Design Arena: agents building Android apps | Not measured | 1021 | Only GPT-5.4 measured |
| Design Arena: agents building Godot games | Not measured | 1135 | Only GPT-5.4 measured |
| Design Arena: spreadsheets | 1434 | Not measured | Only Claude Fable 5.2 measured |
| LiveBench research | 94.5% | Not measured | Only Claude Fable 5.2 measured |
| LiveBench browser | 86.9% | Not measured | Only Claude Fable 5.2 measured |
| LiveBench long agentic | 82.9% | Not measured | Only Claude Fable 5.2 measured |
| Tax Agent Bench (Vals AI) | 32.1% | Not measured | Only Claude Fable 5.2 measured |
| Legal Research Bench (Vals AI) | 46.1% | Not measured | Only Claude Fable 5.2 measured |
| Harvey's Legal Agent Benchmark (Vals AI) | 5.0% | Not measured | Only Claude Fable 5.2 measured |
| BioMysteryBench (Vals AI) | 83.7% | Not measured | Only Claude Fable 5.2 measured |
| Terminal-Bench-Science (Vals AI) | 55.7% | Not measured | Only Claude Fable 5.2 measured |
| Vals Science Index | 63.7% | Not measured | Only Claude Fable 5.2 measured |
| τ²-Bench Telecom | Not measured | 87.1% | Only GPT-5.4 measured |
| APEX-Agents | 80.1% | 52.4% | Claude Fable 5.2 |
| METR time horizons | Not measured | 74.3% | Only GPT-5.4 measured |
| Remote Labor Index | 41.3% | Not measured | Only Claude Fable 5.2 measured |
| DeepResearch Bench | Not measured | 35.1% | Only GPT-5.4 measured |
| PostTrainBench | Not measured | 17.8% | Only GPT-5.4 measured |
| SpireClimb | 15.5% | Not measured | Only Claude Fable 5.2 measured |
| Vending-Bench 2 | Not measured | $6,144 | Only GPT-5.4 measured |
| LMArena Search | Not measured | 1198 | Only GPT-5.4 measured |
| MCP Atlas | Not measured | 70.6% | Only GPT-5.4 measured |
| τ³-Banking | Not measured | 39.4% | Only GPT-5.4 measured |
| Neither model has a result on the other 18 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index70
| Benchmark | Claude Fable 5.2 | GPT-5.4 | Leader |
|---|---|---|---|
| GPQA Diamond | Not measured | 91.7% | Only GPT-5.4 measured |
| LiveBench reasoning | 88.8% | Not measured | Only Claude Fable 5.2 measured |
| MysteryMechanism (Vals AI) | 51.8% | Not measured | Only Claude Fable 5.2 measured |
| MMMU Pro (Vals AI) | Not measured | 87.5% | Only GPT-5.4 measured |
| GPQA Diamond (Artificial Analysis run) | Not measured | 92.0% | Only GPT-5.4 measured |
| Humanity's Last Exam (Artificial Analysis run) | 74.3% | 43.7% | Claude Fable 5.2 |
| HLE-Diamond (Artificial Analysis run) | 80.2% | Not measured | Only Claude Fable 5.2 measured |
| CritPt v2, hard subset (Artificial Analysis run) | 76.5% | Not measured | Only Claude Fable 5.2 measured |
| GPQA Diamond (Epoch AI run) | 93.9% | 93.3% | Claude Fable 5.2 |
| ARC-AGI | 98.5% | 93.7% | Claude Fable 5.2 |
| ARC-AGI-2 | 93.8% | 74.0% | Claude Fable 5.2 |
| SimpleBench | 94.9% | Not measured | Only Claude Fable 5.2 measured |
| Chess puzzles | 79.0% | 48.0% | Claude Fable 5.2 |
| Mystery game puzzles | 90.0% | 37.0% | Claude Fable 5.2 |
| EBR-bench | 90.5% | 25.4% | Claude Fable 5.2 |
| LMArena Text: hard prompts | Not measured | 1485 | Only GPT-5.4 measured |
| LMArena Text: expert | Not measured | 1506 | Only GPT-5.4 measured |
| LMArena Text: hard prompts in English | Not measured | 1479 | Only GPT-5.4 measured |
| LMArena Vision: diagrams | Not measured | 1325 | Only GPT-5.4 measured |
| LMArena Vision: homework | Not measured | 1336 | Only GPT-5.4 measured |
| Kagi LLM Benchmark | Not measured | 63.8% | Only GPT-5.4 measured |
| Humanity's Last Exam (Scale run) | 72.4% | Not measured | Only Claude Fable 5.2 measured |
| GoBench | 2566 | Not measured | Only Claude Fable 5.2 measured |
| Neither model has a result on the other 3 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index50
| Benchmark | Claude Fable 5.2 | GPT-5.4 | Leader |
|---|---|---|---|
| AIME | Not measured | 96.7% | Only GPT-5.4 measured |
| OTIS Mock AIME | 99.7% | 97.8% | Claude Fable 5.2 |
| FrontierMath, tiers 1 to 3 | 95.1% | 78.6% | Claude Fable 5.2 |
| FrontierMath, tier 4 | 100.0% | 49.0% | Claude Fable 5.2 |
| ProofBench | 100.0% | 56.0% | Claude Fable 5.2 |
| LMArena Text: math | Not measured | 1487 | Only GPT-5.4 measured |
| LMArena Text: mathematical work | Not measured | 1496 | Only GPT-5.4 measured |
| MathArena | 82.8% | 34.2% | Claude Fable 5.2 |
| Neither model has a result on the other 6 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index30
| Benchmark | Claude Fable 5.2 | GPT-5.4 | Leader |
|---|---|---|---|
| MMLU Pro | Not measured | 87.5% | Only GPT-5.4 measured |
| LegalBench (Vals AI) | Not measured | 86.0% | Only GPT-5.4 measured |
| CaseLaw (Vals AI) | Not measured | 63.8% | Only GPT-5.4 measured |
| CorpFin (Vals AI) | Not measured | 65.3% | Only GPT-5.4 measured |
| TaxEval (Vals AI) | Not measured | 74.0% | Only GPT-5.4 measured |
| MortgageTax (Vals AI) | Not measured | 68.3% | Only GPT-5.4 measured |
| MedQA (Vals AI) | Not measured | 96.1% | Only GPT-5.4 measured |
| MedCode (Vals AI) | Not measured | 41.3% | Only GPT-5.4 measured |
| AA-Omniscience | 66.8 | Not measured | Only Claude Fable 5.2 measured |
| SimpleQA Verified | 94.0% | 45.1% | Claude Fable 5.2 |
| LMArena Text: science | Not measured | 1478 | Only GPT-5.4 measured |
| LMArena Text: medicine and healthcare | Not measured | 1458 | Only GPT-5.4 measured |
| LMArena Text: legal and government | Not measured | 1485 | Only GPT-5.4 measured |
| LMArena Text: business and finance | Not measured | 1475 | Only GPT-5.4 measured |
| PRBench Finance | 47.1% | 45.6% | Claude Fable 5.2 |
| PRBench Legal | 49.0% | 44.4% | Claude Fable 5.2 |
| Neither model has a result on the other 5 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index50
| Benchmark | Claude Fable 5.2 | GPT-5.4 | Leader |
|---|---|---|---|
| Design Arena: websites | 1351 | 1190 | Claude Fable 5.2 |
| Design Arena: UI components | 1371 | 1205 | Claude Fable 5.2 |
| Design Arena: game dev | 1396 | 1183 | Claude Fable 5.2 |
| Design Arena: data viz | Not measured | 1193 | Only GPT-5.4 measured |
| Design Arena: 3D | 1517 | 1045 | Claude Fable 5.2 |
| Design Arena: all code categories | 1373 | 1169 | Claude Fable 5.2 |
| Design Arena: SVG | Not measured | 1131 | Only GPT-5.4 measured |
| Design Arena: ASCII art | Not measured | 1183 | Only GPT-5.4 measured |
| LiveBench design | 85.1% | Not measured | Only Claude Fable 5.2 measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index50
| Benchmark | Claude Fable 5.2 | GPT-5.4 | Leader |
|---|---|---|---|
| Vals Index | 71.3% | Not measured | Only Claude Fable 5.2 measured |
| LiveBench data analysis | 81.5% | Not measured | Only Claude Fable 5.2 measured |
| MedScribe (Vals AI) | Not measured | 77.5% | Only GPT-5.4 measured |
| IFBench | Not measured | 73.9% | Only GPT-5.4 measured |
| Long context reasoning (AA-LCR) | 83.3% | 82.0% | Claude Fable 5.2 |
| GDPval-AA | 1831 | 1256 | Claude Fable 5.2 |
| DTBench | 99.2% | 94.4% | Claude Fable 5.2 |
| LMCA | 70.6% | 52.0% | Claude Fable 5.2 |
| CL-bench | Not measured | 27.9% | Only GPT-5.4 measured |
| Furniture assembly | 90.0% | 37.5% | Claude Fable 5.2 |
| CL-bench Life | Not measured | 21.7% | Only GPT-5.4 measured |
| LMArena Text | Not measured | 1469 | Only GPT-5.4 measured |
| LMArena Text: instruction following | Not measured | 1469 | Only GPT-5.4 measured |
| LMArena Text: creative writing | Not measured | 1437 | Only GPT-5.4 measured |
| LMArena Vision | Not measured | 1301 | Only GPT-5.4 measured |
| LMArena Text: English | Not measured | 1467 | Only GPT-5.4 measured |
| LMArena Text: non-English | Not measured | 1465 | Only GPT-5.4 measured |
| LMArena Text: Chinese | Not measured | 1518 | Only GPT-5.4 measured |
| LMArena Text: German | Not measured | 1472 | Only GPT-5.4 measured |
| LMArena Text: Japanese | Not measured | 1481 | Only GPT-5.4 measured |
| LMArena Text: Korean | Not measured | 1448 | Only GPT-5.4 measured |
| LMArena Text: French | Not measured | 1493 | Only GPT-5.4 measured |
| LMArena Text: Spanish | Not measured | 1453 | Only GPT-5.4 measured |
| LMArena Text: Russian | Not measured | 1481 | Only GPT-5.4 measured |
| LMArena Text: Polish | Not measured | 1473 | Only GPT-5.4 measured |
| LMArena Text: multi-turn | Not measured | 1482 | Only GPT-5.4 measured |
| LMArena Text: longer queries | Not measured | 1473 | Only GPT-5.4 measured |
| LMArena Text: writing and language | Not measured | 1457 | Only GPT-5.4 measured |
| LMArena Text: entertainment and media | Not measured | 1437 | Only GPT-5.4 measured |
| LMArena Vision: English | Not measured | 1299 | Only GPT-5.4 measured |
| LMArena Vision: Chinese | Not measured | 1354 | Only GPT-5.4 measured |
| LMArena Vision: reading text | Not measured | 1310 | Only GPT-5.4 measured |
| LMArena Vision: humor | Not measured | 1288 | Only GPT-5.4 measured |
| LMArena Vision: recognizing things | Not measured | 1247 | Only GPT-5.4 measured |
| LMArena Vision: creative writing | Not measured | 1285 | Only GPT-5.4 measured |
| LMArena Document | Not measured | 1473 | Only GPT-5.4 measured |
| EQ-Bench 4 | Not measured | 1258 | Only GPT-5.4 measured |
| 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
| Benchmark | Claude Fable 5.2 | GPT-5.4 | 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 5.2$0.028Fits in one request
GPT-5.4$0.010Fits in one request
GPT-5.4 costs less
Repository review
50K input + 3K output tokens
Claude Fable 5.2$0.520Fits in one request
GPT-5.4$0.170Fits in one request
GPT-5.4 costs less
Agent loop
200K input + 10K output tokens
Claude Fable 5.2$2.00Fits in one request
GPT-5.4$0.650Fits in one request
GPT-5.4 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 | Anthropic Claude Fable 5.2 | OpenAI GPT-5.4 |
|---|---|---|
| Maker | Anthropic | OpenAI |
| Weights | No public weights listed | No public weights listed |
| Released | November 9, 2026 | March 5, 2026 |
| Context window | 1M | 1.05M |
| Input $/Mtok | $8.00 | $2.50 |
| Output $/Mtok | $40.00 | $15.00 |
| Coding index | 87.8 | 64.3 |
| Independent measurements behind it | 4 | 3 |
| Cost per solved task | Not computable | $1.02 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Fable 5.2 better than GPT-5.4 for coding?
Pick Claude Fable 5.2 for coding: it scores 87.8 on the Vibe Coding Index against 64.3 for GPT-5.4. Pick GPT-5.4 for output tokens 2.7x cheaper ($15.00 vs $40.00 per million) and a larger context window (1.05M against 1M tokens).
Which is cheaper, Claude Fable 5.2 or GPT-5.4?
Claude Fable 5.2 costs $8.00 per million input tokens and $40.00 per million output tokens; GPT-5.4 costs $2.50 and $15.00. Cost per solved task is known for GPT-5.4 only.
Which has the bigger context window, Claude Fable 5.2 or GPT-5.4?
GPT-5.4, with 1.05M tokens against 1M.
How many benchmarks is the Claude Fable 5.2 vs GPT-5.4 comparison based on?
36 benchmarks have a result for both models as of November 14, 2026. Claude Fable 5.2's coding index rests on 4 independent benchmarks and GPT-5.4's on 3. Where only one model has a result, the page says so instead of naming a winner.