GPT-5.4 vs Step 5 Preview
GPT-5.4 leads Step 5 Preview on coding, 64.4 to 61.1 on the Vibe Coding Index, and Step 5 Preview costs 5.6x less per output token ($2.70 vs $15.00 per million). Updated October 22, 2026; 40 benchmarks have a result for both.
GPT-5.4 or Step 5 Preview: which to pick
Pick GPT-5.4 for coding: it scores 64.4 on the Vibe Coding Index against 61.1 for Step 5 Preview, though on 3 benchmarks against 4.
Pick Step 5 Preview for output tokens 5.6x cheaper ($2.70 vs $15.00 per million) and work measured by LMArena WebDev or Vibe Code Bench (Vals AI), where it leads.
- Shared results
- 40
- GPT-5.4 only
- 70
- Step 5 Preview only
- 21
- 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-5.4
GPT-5.4 scores 64.4 against 61.1.
3 and 4 benchmarks behind the scores
Intelligence
AA Intelligence Index
Step 5 Preview
Step 5 Preview leads, 43.7 against 39.0.
Same board, both measured
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
No call
Only GPT-5.4 has a Design Arena: websites result, 1198.
Directional only
Long documents
Listed context window
GPT-5.4
GPT-5.4 takes 1.05M tokens against 1.05M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Step 5 Preview
GPT-5.4 $0.010, Step 5 Preview $0.0024 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
- GPT-5.4 64.4 from 3 benchmarks, Step 5 Preview 61.1 from 4 benchmarks.
- Widest category
- Coding, 10.0 points apart on average over 8 shared benchmarks.
- Widest single gap
- LMArena WebDev: React: GPT-5.4 1454 against Step 5 Preview 1583, 21.5 points apart on a 0 to 100 scale.
- Output price
- GPT-5.4 $15.00 against Step 5 Preview $2.70 per million output tokens, 5.6x apart.
- Context window
- GPT-5.4 takes 1.05M tokens, Step 5 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.
| Category | GPT-5.4 | Bars | Step 5 Preview | Ties |
|---|---|---|---|---|
| Coding | 2 | 6 | ||
| Intelligence | 0 | 1 | ||
| Reasoning | 5 | 1 | ||
| Math | 3 | 0 | ||
| Knowledge | 4 | 0 | ||
| General | 17 | 1 | ||
| All shared boards | 31 | 9 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index26
| Benchmark | GPT-5.4 | Step 5 Preview | Leader |
|---|---|---|---|
| LiveBench coding | Not measured | 85.6% | Only Step 5 Preview measured |
| LMArena WebDev | 1464 | 1567 | Step 5 Preview |
| AA Coding Index | 71.1 | Not measured | Only GPT-5.4 measured |
| LiveCodeBench (Vals AI) | 84.1% | Not measured | Only GPT-5.4 measured |
| SWE-bench Verified (Vals AI) | 78.2% | Not measured | Only GPT-5.4 measured |
| Terminal-Bench 4 (Vals AI) | Not measured | 31.8% | Only Step 5 Preview measured |
| Vibe Code Bench (Vals AI) | 67.4% | 70.4% | Step 5 Preview |
| Code migration (Vals AI) | 35.0% | 39.0% | Step 5 Preview |
| ProgramBench (Vals AI) | 0.5% | Not measured | Only GPT-5.4 measured |
| IOI (Vals AI) | Not measured | 38.1% | Only Step 5 Preview measured |
| SWE-bench Multimodal (Vals AI) | Not measured | 40.8% | Only Step 5 Preview measured |
| SkillsBench (Vals AI) | 51.7% | Not measured | Only GPT-5.4 measured |
| SciCode | Not measured | 58.9% | Only Step 5 Preview measured |
| Terminal-Bench Hard (Artificial Analysis run) | 57.6% | Not measured | Only GPT-5.4 measured |
| Terminal-Bench | 81.8% | Not measured | Only GPT-5.4 measured |
| GSO-Bench | 31.4% | Not measured | Only GPT-5.4 measured |
| WeirdML | 77.7% | Not measured | Only GPT-5.4 measured |
| MirrorCode | 15.6% | Not measured | Only GPT-5.4 measured |
| ALE-Bench | 1607.0 | Not measured | Only GPT-5.4 measured |
| LMArena Text: coding | 1496 | 1485 | GPT-5.4 |
| LMArena Text: software and IT | 1491 | 1473 | GPT-5.4 |
| LMArena WebDev: React | 1454 | 1583 | Step 5 Preview |
| LMArena WebDev: HTML | 1478 | 1556 | Step 5 Preview |
| LMArena WebDev: from an image | 1436 | 1550 | Step 5 Preview |
| Neither model has a result on the other 15 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | GPT-5.4 | Step 5 Preview | Leader |
|---|---|---|---|
| AA Intelligence Index | 39.0 | 43.7 | Step 5 Preview |
| Epoch Capabilities Index | 157.3 | Not measured | Only GPT-5.4 measured |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index22 boards, none shared
| Benchmark | GPT-5.4 | Step 5 Preview | Leader |
|---|---|---|---|
| Design Arena: agents building web apps | 1059 | Not measured | Only GPT-5.4 measured |
| Design Arena: agents building full-stack apps | 1017 | Not measured | Only GPT-5.4 measured |
| Design Arena: agents building mobile apps | 1087 | Not measured | Only GPT-5.4 measured |
| Design Arena: agents building Android apps | 1031 | Not measured | Only GPT-5.4 measured |
| Design Arena: agents building Godot games | 1135 | Not measured | Only GPT-5.4 measured |
| LiveBench research | Not measured | 72.8% | Only Step 5 Preview measured |
| LiveBench browser | Not measured | 24.0% | Only Step 5 Preview measured |
| LiveBench long agentic | Not measured | 27.5% | Only Step 5 Preview measured |
| SREBench (Vals AI) | Not measured | 0.4% | Only Step 5 Preview measured |
| Finance Agent (Vals AI) | Not measured | 50.7% | Only Step 5 Preview measured |
| Tax Agent Bench (Vals AI) | Not measured | 27.3% | Only Step 5 Preview measured |
| Legal Research Bench (Vals AI) | Not measured | 40.4% | Only Step 5 Preview measured |
| Excel Modeling Benchmark (Vals AI) | Not measured | 57.1% | Only Step 5 Preview measured |
| BioMysteryBench (Vals AI) | Not measured | 67.4% | Only Step 5 Preview measured |
| Terminal-Bench-Science (Vals AI) | Not measured | 2.9% | Only Step 5 Preview measured |
| Vals Science Index | Not measured | 29.6% | Only Step 5 Preview measured |
| τ²-Bench Telecom | 87.1% | Not measured | Only GPT-5.4 measured |
| APEX-Agents | 52.4% | Not measured | Only GPT-5.4 measured |
| METR time horizons | 74.3% | Not measured | Only GPT-5.4 measured |
| DeepResearch Bench | 35.1% | Not measured | Only GPT-5.4 measured |
| PostTrainBench | 19.0% | Not measured | Only GPT-5.4 measured |
| Vending-Bench 2 | $6,144 | Not measured | Only GPT-5.4 measured |
| Neither model has a result on the other 19 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index51
| Benchmark | GPT-5.4 | Step 5 Preview | Leader |
|---|---|---|---|
| GPQA Diamond | 91.7% | Not measured | Only GPT-5.4 measured |
| LiveBench reasoning | Not measured | 83.8% | Only Step 5 Preview measured |
| MysteryMechanism (Vals AI) | Not measured | 18.5% | Only Step 5 Preview measured |
| MMMU Pro (Vals AI) | 87.5% | Not measured | Only GPT-5.4 measured |
| GPQA Diamond (Artificial Analysis run) | 92.0% | Not measured | Only GPT-5.4 measured |
| Humanity's Last Exam (Artificial Analysis run) | 43.7% | 46.5% | Step 5 Preview |
| GPQA Diamond (Epoch AI run) | 93.3% | Not measured | Only GPT-5.4 measured |
| ARC-AGI | 93.7% | Not measured | Only GPT-5.4 measured |
| ARC-AGI-2 | 74.0% | Not measured | Only GPT-5.4 measured |
| Chess puzzles | 48.0% | Not measured | Only GPT-5.4 measured |
| Mystery game puzzles | 37.0% | Not measured | Only GPT-5.4 measured |
| EBR-bench | 25.4% | Not measured | Only GPT-5.4 measured |
| LMArena Text: hard prompts | 1485 | 1461 | GPT-5.4 |
| LMArena Text: expert | 1507 | 1485 | GPT-5.4 |
| LMArena Text: hard prompts in English | 1479 | 1454 | GPT-5.4 |
| LMArena Vision: diagrams | 1327 | 1308 | GPT-5.4 |
| LMArena Vision: homework | 1336 | 1265 | GPT-5.4 |
| Kagi LLM Benchmark | 63.8% | Not measured | Only GPT-5.4 measured |
| Neither model has a result on the other 4 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index30
| Benchmark | GPT-5.4 | Step 5 Preview | Leader |
|---|---|---|---|
| AIME | 96.7% | Not measured | Only GPT-5.4 measured |
| OTIS Mock AIME | 97.8% | Not measured | Only GPT-5.4 measured |
| FrontierMath, tiers 1 to 3 | 78.6% | Not measured | Only GPT-5.4 measured |
| FrontierMath, tier 4 | 49.0% | Not measured | Only GPT-5.4 measured |
| ProofBench | 56.0% | 42.0% | GPT-5.4 |
| LMArena Text: math | 1488 | 1458 | GPT-5.4 |
| LMArena Text: mathematical work | 1497 | 1460 | GPT-5.4 |
| Neither model has a result on the other 6 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index40
| Benchmark | GPT-5.4 | Step 5 Preview | Leader |
|---|---|---|---|
| MMLU Pro | 87.5% | Not measured | Only GPT-5.4 measured |
| LegalBench (Vals AI) | 86.0% | Not measured | Only GPT-5.4 measured |
| CaseLaw (Vals AI) | 63.8% | Not measured | Only GPT-5.4 measured |
| CorpFin (Vals AI) | 65.3% | Not measured | Only GPT-5.4 measured |
| TaxEval (Vals AI) | 74.0% | Not measured | Only GPT-5.4 measured |
| MortgageTax (Vals AI) | 68.3% | Not measured | Only GPT-5.4 measured |
| MedQA (Vals AI) | 96.1% | Not measured | Only GPT-5.4 measured |
| MedCode (Vals AI) | 41.3% | Not measured | Only GPT-5.4 measured |
| SimpleQA Verified | 45.1% | Not measured | Only GPT-5.4 measured |
| LMArena Text: science | 1479 | 1454 | GPT-5.4 |
| LMArena Text: medicine and healthcare | 1458 | 1439 | GPT-5.4 |
| LMArena Text: legal and government | 1486 | 1437 | GPT-5.4 |
| LMArena Text: business and finance | 1474 | 1435 | GPT-5.4 |
| Neither model has a result on the other 5 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index9 boards, none shared
| Benchmark | GPT-5.4 | Step 5 Preview | Leader |
|---|---|---|---|
| Design Arena: websites | 1198 | Not measured | Only GPT-5.4 measured |
| Design Arena: UI components | 1212 | Not measured | Only GPT-5.4 measured |
| Design Arena: game dev | 1194 | Not measured | Only GPT-5.4 measured |
| Design Arena: data viz | 1196 | Not measured | Only GPT-5.4 measured |
| Design Arena: 3D | 1065 | Not measured | Only GPT-5.4 measured |
| Design Arena: all code categories | 1179 | Not measured | Only GPT-5.4 measured |
| Design Arena: SVG | 1141 | Not measured | Only GPT-5.4 measured |
| Design Arena: ASCII art | 1188 | Not measured | Only GPT-5.4 measured |
| LiveBench design | Not measured | 76.9% | Only Step 5 Preview measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index171
| Benchmark | GPT-5.4 | Step 5 Preview | Leader |
|---|---|---|---|
| LiveBench data analysis | Not measured | 63.5% | Only Step 5 Preview measured |
| Public Benefits Bench (Vals AI) | Not measured | 58.1% | Only Step 5 Preview measured |
| SAGE (Vals AI) | 43.3% | Not measured | Only GPT-5.4 measured |
| MedScribe (Vals AI) | 77.5% | Not measured | Only GPT-5.4 measured |
| IFBench | 73.9% | Not measured | Only GPT-5.4 measured |
| Long context reasoning (AA-LCR) | 82.0% | 88.3% | Step 5 Preview |
| DTBench | 94.4% | Not measured | Only GPT-5.4 measured |
| LMCA | 52.0% | Not measured | Only GPT-5.4 measured |
| CL-bench | 27.9% | Not measured | Only GPT-5.4 measured |
| Furniture assembly | 37.5% | Not measured | Only GPT-5.4 measured |
| CL-bench Life | 21.7% | Not measured | Only GPT-5.4 measured |
| LMArena Text | 1469 | 1440 | GPT-5.4 |
| LMArena Text: instruction following | 1469 | 1438 | GPT-5.4 |
| LMArena Text: creative writing | 1439 | 1409 | GPT-5.4 |
| LMArena Vision | 1303 | 1265 | GPT-5.4 |
| LMArena Text: English | 1467 | 1447 | GPT-5.4 |
| LMArena Text: non-English | 1465 | 1428 | GPT-5.4 |
| LMArena Text: Chinese | 1520 | 1500 | GPT-5.4 |
| LMArena Text: German | 1472 | Not measured | Only GPT-5.4 measured |
| LMArena Text: Japanese | 1485 | 1383 | GPT-5.4 |
| LMArena Text: Korean | 1449 | Not measured | Only GPT-5.4 measured |
| LMArena Text: French | 1493 | 1438 | GPT-5.4 |
| LMArena Text: Spanish | 1452 | 1441 | GPT-5.4 |
| LMArena Text: Russian | 1480 | 1433 | GPT-5.4 |
| LMArena Text: Polish | 1472 | Not measured | Only GPT-5.4 measured |
| LMArena Text: multi-turn | 1482 | 1437 | GPT-5.4 |
| LMArena Text: longer queries | 1473 | 1449 | GPT-5.4 |
| LMArena Text: writing and language | 1458 | 1425 | GPT-5.4 |
| LMArena Text: entertainment and media | 1438 | 1412 | GPT-5.4 |
| LMArena Vision: English | 1301 | 1290 | GPT-5.4 |
| LMArena Vision: Chinese | 1354 | Not measured | Only GPT-5.4 measured |
| LMArena Vision: reading text | 1312 | 1282 | GPT-5.4 |
| LMArena Vision: humor | 1284 | Not measured | Only GPT-5.4 measured |
| LMArena Vision: recognizing things | 1251 | Not measured | Only GPT-5.4 measured |
| LMArena Vision: creative writing | 1283 | Not measured | Only GPT-5.4 measured |
| LMArena Document | 1471 | Not measured | Only GPT-5.4 measured |
| Neither model has a result on the other 10 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | GPT-5.4 | Step 5 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
Step 5 Preview costs less
Repository review
50K input + 3K output tokens
Step 5 Preview costs less
Agent loop
200K input + 10K output tokens
Step 5 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.
| Specification | OpenAI GPT-5.4 | StepFun Step 5 Preview |
|---|---|---|
| Maker | OpenAI | StepFun |
| Weights | No public weights listed | Open weights |
| Released | March 5, 2026 | October 8, 2026 |
| Context window | 1.05M | 1.05M |
| Input $/Mtok | $2.50 | $1.00 |
| Output $/Mtok | $15.00 | $2.70 |
| Coding index | 64.4 | 61.1 |
| Independent measurements behind it | 3 | 4 |
| Cost per solved task | $1.02 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GPT-5.4 better than Step 5 Preview for coding?
Pick GPT-5.4 for coding: it scores 64.4 on the Vibe Coding Index against 61.1 for Step 5 Preview, though on 3 benchmarks against 4. Pick Step 5 Preview for output tokens 5.6x cheaper ($2.70 vs $15.00 per million) and work measured by LMArena WebDev or Vibe Code Bench (Vals AI), where it leads.
Which is cheaper, GPT-5.4 or Step 5 Preview?
GPT-5.4 costs $2.50 per million input tokens and $15.00 per million output tokens; Step 5 Preview costs $1.00 and $2.70. Cost per solved task is known for GPT-5.4 only.
Which has the bigger context window, GPT-5.4 or Step 5 Preview?
GPT-5.4, with 1.05M tokens against 1.05M.
How many benchmarks is the GPT-5.4 vs Step 5 Preview comparison based on?
40 benchmarks have a result for both models as of October 22, 2026. GPT-5.4's coding index rests on 3 independent benchmarks and Step 5 Preview's on 4. Where only one model has a result, the page says so instead of naming a winner.