Grok 4.5 vs Step 5 Preview
Step 5 Preview leads Grok 4.5 on coding, 61.1 to 58.6 on the Vibe Coding Index, and Step 5 Preview costs 2.2x less per output token ($2.70 vs $6.00 per million). Updated October 22, 2026; 55 benchmarks have a result for both.
Grok 4.5 or Step 5 Preview: which to pick
Pick Step 5 Preview for coding: it scores 61.1 on the Vibe Coding Index against 58.6 for Grok 4.5, though on 4 benchmarks against 6.
Pick Grok 4.5 for work measured by LiveBench coding or IOI (Vals AI), where it leads.
- Shared results
- 55
- Grok 4.5 only
- 68
- Step 5 Preview only
- 6
- 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
Step 5 Preview
Step 5 Preview scores 61.1 against 58.6.
6 and 4 benchmarks behind the scores
Intelligence
AA Intelligence Index
Step 5 Preview
Step 5 Preview leads, 43.7 against 38.8.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only Grok 4.5 has a AA Agentic Index result, 41.2.
Directional only
Reasoning
GPQA Diamond
No call
Only Grok 4.5 has a GPQA Diamond result, 92.9%.
Directional only
Knowledge
MMLU Pro
No call
Only Grok 4.5 has a MMLU Pro result, 89.2%.
Directional only
Web design
Design Arena: websites
No call
Only Grok 4.5 has a Design Arena: websites result, 1281.
Directional only
Long documents
Listed context window
Step 5 Preview
Step 5 Preview takes 1.05M tokens against 500K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Step 5 Preview
Grok 4.5 $0.0050, Step 5 Preview $0.0024 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Grok 4.5 has the number, $0.62.
Directional only
At a glance
- Coding index
- Grok 4.5 58.6 from 6 benchmarks, Step 5 Preview 61.1 from 4 benchmarks.
- Widest category
- Agentic work, 5.7 points apart on average over 8 shared benchmarks.
- Widest single gap
- Terminal-Bench 4 (Vals AI): Grok 4.5 8.6% against Step 5 Preview 31.8%, 31.0 points apart on a 0 to 100 scale.
- Output price
- Grok 4.5 $6.00 against Step 5 Preview $2.70 per million output tokens, 2.2x apart.
- Context window
- Grok 4.5 takes 500K 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 | Grok 4.5 | Bars | Step 5 Preview | Ties |
|---|---|---|---|---|
| Coding | 4 | 8 | ||
| Intelligence | 0 | 1 | ||
| Agentic work | 4 | 4 | ||
| Reasoning | 4 | 3 | ||
| Math | 2 | 1 | ||
| Knowledge | 4 | 0 | ||
| Web design | 1 | 0 | ||
| General | 16 | 3 | ||
| All shared boards | 35 | 20 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index48
| Benchmark | Grok 4.5 | Step 5 Preview | Leader |
|---|---|---|---|
| LiveBench coding | 94.3% | 85.6% | Grok 4.5 |
| LMArena WebDev | 1553 | 1567 | Step 5 Preview |
| AA Coding Index | 72.4 | Not measured | Only Grok 4.5 measured |
| LiveCodeBench (Vals AI) | 87.3% | Not measured | Only Grok 4.5 measured |
| SWE-bench Verified (Vals AI) | 86.6% | Not measured | Only Grok 4.5 measured |
| Terminal-Bench 4 (Vals AI) | 8.6% | 31.8% | Step 5 Preview |
| Vibe Code Bench (Vals AI) | 69.0% | 70.4% | Step 5 Preview |
| Code migration (Vals AI) | 36.6% | 39.0% | Step 5 Preview |
| ProgramBench (Vals AI) | 0.0% | Not measured | Only Grok 4.5 measured |
| IOI (Vals AI) | 40.6% | 38.1% | Grok 4.5 |
| Terminal-Bench 2.1 (Vals AI) | 67.8% | Not measured | Only Grok 4.5 measured |
| SWE-bench Multimodal (Vals AI) | Not measured | 40.8% | Only Step 5 Preview measured |
| SkillsBench (Vals AI) | 66.0% | Not measured | Only Grok 4.5 measured |
| CyberBench (Vals AI) | 71.0% | Not measured | Only Grok 4.5 measured |
| SciCode | 55.0% | 58.9% | Step 5 Preview |
| FrontierCode | 42.4% | Not measured | Only Grok 4.5 measured |
| WeirdML | 46.4% | Not measured | Only Grok 4.5 measured |
| ALE-Bench | 1309.3 | Not measured | Only Grok 4.5 measured |
| LMArena Text: coding | 1474 | 1485 | Step 5 Preview |
| LMArena Text: software and IT | 1471 | 1473 | Step 5 Preview |
| LMArena WebDev: React | 1556 | 1583 | Step 5 Preview |
| LMArena WebDev: HTML | 1567 | 1556 | Grok 4.5 |
| LMArena WebDev: from an image | 1562 | 1550 | Grok 4.5 |
| SciCode | 6.5% | Not measured | Only Grok 4.5 measured |
| Neither model has a result on the other 15 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Grok 4.5 | Step 5 Preview | Leader |
|---|---|---|---|
| AA Intelligence Index | 38.8 | 43.7 | Step 5 Preview |
| Epoch Capabilities Index | 154.1 | Not measured | Only Grok 4.5 measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index44
| Benchmark | Grok 4.5 | Step 5 Preview | Leader |
|---|---|---|---|
| AA Agentic Index | 41.2 | Not measured | Only Grok 4.5 measured |
| Design Arena: agents building web apps | 1218 | Not measured | Only Grok 4.5 measured |
| Design Arena: agents building full-stack apps | 1249 | Not measured | Only Grok 4.5 measured |
| Design Arena: agents building mobile apps | 1220 | Not measured | Only Grok 4.5 measured |
| Design Arena: agents building Android apps | 1236 | Not measured | Only Grok 4.5 measured |
| Design Arena: agents building Godot games | 1229 | Not measured | Only Grok 4.5 measured |
| Design Arena: agents building games | 1236 | Not measured | Only Grok 4.5 measured |
| Design Arena: HTML slides | 1205 | Not measured | Only Grok 4.5 measured |
| Design Arena: PowerPoint slides | 1230 | Not measured | Only Grok 4.5 measured |
| LiveBench research | 85.9% | 72.8% | Grok 4.5 |
| LiveBench browser | 44.0% | 24.0% | Grok 4.5 |
| LiveBench long agentic | 27.9% | 27.5% | Grok 4.5 |
| SREBench (Vals AI) | 0.8% | 0.4% | Grok 4.5 |
| Finance Agent (Vals AI) | 48.4% | 50.7% | Step 5 Preview |
| Tax Agent Bench (Vals AI) | 24.9% | 27.3% | Step 5 Preview |
| Legal Research Bench (Vals AI) | 38.0% | 40.4% | Step 5 Preview |
| Excel Modeling Benchmark (Vals AI) | 52.9% | 57.1% | Step 5 Preview |
| 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 |
| Time Horizon Index (Vals AI) | 6.3% | Not measured | Only Grok 4.5 measured |
| APEX-Agents | 56.2% | Not measured | Only Grok 4.5 measured |
| PostTrainBench | 23.4% | Not measured | Only Grok 4.5 measured |
| Vending-Bench 2 | $3,887 | Not measured | Only Grok 4.5 measured |
| LMArena Search | 1216 | Not measured | Only Grok 4.5 measured |
| Neither model has a result on the other 16 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index43
| Benchmark | Grok 4.5 | Step 5 Preview | Leader |
|---|---|---|---|
| GPQA Diamond | 92.9% | Not measured | Only Grok 4.5 measured |
| LiveBench reasoning | 87.2% | 83.8% | Grok 4.5 |
| MysteryMechanism (Vals AI) | Not measured | 18.5% | Only Step 5 Preview measured |
| MMMU Pro (Vals AI) | 61.8% | Not measured | Only Grok 4.5 measured |
| GPQA Diamond (Artificial Analysis run) | 93.1% | Not measured | Only Grok 4.5 measured |
| Humanity's Last Exam (Artificial Analysis run) | 42.7% | 46.5% | Step 5 Preview |
| GPQA Diamond (Epoch AI run) | 93.4% | Not measured | Only Grok 4.5 measured |
| ARC-AGI | 87.2% | Not measured | Only Grok 4.5 measured |
| ARC-AGI-2 | 52.6% | Not measured | Only Grok 4.5 measured |
| SimpleBench | 70.0% | Not measured | Only Grok 4.5 measured |
| Chess puzzles | 35.0% | Not measured | Only Grok 4.5 measured |
| LMArena Text: hard prompts | 1462 | 1461 | Grok 4.5 |
| LMArena Text: expert | 1465 | 1485 | Step 5 Preview |
| LMArena Text: hard prompts in English | 1464 | 1454 | Grok 4.5 |
| LMArena Vision: diagrams | 1304 | 1308 | Step 5 Preview |
| LMArena Vision: homework | 1295 | 1265 | Grok 4.5 |
| Kagi LLM Benchmark | 83.5% | Not measured | Only Grok 4.5 measured |
| Neither model has a result on the other 5 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index21
| Benchmark | Grok 4.5 | Step 5 Preview | Leader |
|---|---|---|---|
| OTIS Mock AIME | 97.8% | Not measured | Only Grok 4.5 measured |
| FrontierMath, tiers 1 to 3 | 57.2% | Not measured | Only Grok 4.5 measured |
| FrontierMath, tier 4 | 24.4% | Not measured | Only Grok 4.5 measured |
| ProofBench | 31.0% | 42.0% | Step 5 Preview |
| LMArena Text: math | 1460 | 1458 | Grok 4.5 |
| LMArena Text: mathematical work | 1482 | 1460 | Grok 4.5 |
| Neither model has a result on the other 7 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index40
| Benchmark | Grok 4.5 | Step 5 Preview | Leader |
|---|---|---|---|
| MMLU Pro | 89.2% | Not measured | Only Grok 4.5 measured |
| LegalBench (Vals AI) | 86.0% | Not measured | Only Grok 4.5 measured |
| CorpFin (Vals AI) | 67.4% | Not measured | Only Grok 4.5 measured |
| TaxEval (Vals AI) | 71.7% | Not measured | Only Grok 4.5 measured |
| MortgageTax (Vals AI) | 61.8% | Not measured | Only Grok 4.5 measured |
| MedCode (Vals AI) | 43.3% | Not measured | Only Grok 4.5 measured |
| SimpleQA Verified | 48.3% | Not measured | Only Grok 4.5 measured |
| LMArena Text: science | 1464 | 1454 | Grok 4.5 |
| LMArena Text: medicine and healthcare | 1440 | 1439 | Grok 4.5 |
| LMArena Text: legal and government | 1463 | 1437 | Grok 4.5 |
| LMArena Text: business and finance | 1441 | 1435 | Grok 4.5 |
| FACTS Benchmark Suite | 50.2% | Not measured | Only Grok 4.5 measured |
| Neither model has a result on the other 6 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Grok 4.5 | Step 5 Preview | Leader |
|---|---|---|---|
| Design Arena: websites | 1281 | Not measured | Only Grok 4.5 measured |
| Design Arena: UI components | 1280 | Not measured | Only Grok 4.5 measured |
| Design Arena: game dev | 1264 | Not measured | Only Grok 4.5 measured |
| Design Arena: data viz | 1266 | Not measured | Only Grok 4.5 measured |
| Design Arena: 3D | 1257 | Not measured | Only Grok 4.5 measured |
| Design Arena: all code categories | 1275 | Not measured | Only Grok 4.5 measured |
| Design Arena: SVG | 1215 | Not measured | Only Grok 4.5 measured |
| Design Arena: ASCII art | 1256 | Not measured | Only Grok 4.5 measured |
| LiveBench design | 78.1% | 76.9% | Grok 4.5 |
GeneralLike-for-likePublic boards, shown as published, kept out of the index163
| Benchmark | Grok 4.5 | Step 5 Preview | Leader |
|---|---|---|---|
| LiveBench data analysis | 73.0% | 63.5% | Grok 4.5 |
| Public Benefits Bench (Vals AI) | Not measured | 58.1% | Only Step 5 Preview measured |
| SAGE (Vals AI) | 35.0% | Not measured | Only Grok 4.5 measured |
| MedScribe (Vals AI) | 86.9% | Not measured | Only Grok 4.5 measured |
| Vals Multimodal Index | 63.4% | Not measured | Only Grok 4.5 measured |
| Long context reasoning (AA-LCR) | 79.3% | 88.3% | Step 5 Preview |
| DTBench | 96.5% | Not measured | Only Grok 4.5 measured |
| LMCA | 45.2% | Not measured | Only Grok 4.5 measured |
| Surface Evolver Bench | 74.4% | Not measured | Only Grok 4.5 measured |
| Furniture assembly | 22.5% | Not measured | Only Grok 4.5 measured |
| LMArena Text | 1448 | 1440 | Grok 4.5 |
| LMArena Text: instruction following | 1445 | 1438 | Grok 4.5 |
| LMArena Text: creative writing | 1442 | 1409 | Grok 4.5 |
| LMArena Vision | 1287 | 1265 | Grok 4.5 |
| LMArena Text: English | 1453 | 1447 | Grok 4.5 |
| LMArena Text: non-English | 1440 | 1428 | Grok 4.5 |
| LMArena Text: Chinese | 1495 | 1500 | Step 5 Preview |
| LMArena Text: German | 1448 | Not measured | Only Grok 4.5 measured |
| LMArena Text: Japanese | 1430 | 1383 | Grok 4.5 |
| LMArena Text: Korean | 1406 | Not measured | Only Grok 4.5 measured |
| LMArena Text: French | 1457 | 1438 | Grok 4.5 |
| LMArena Text: Spanish | 1451 | 1441 | Grok 4.5 |
| LMArena Text: Russian | 1449 | 1433 | Grok 4.5 |
| LMArena Text: Polish | 1432 | Not measured | Only Grok 4.5 measured |
| LMArena Text: multi-turn | 1456 | 1437 | Grok 4.5 |
| LMArena Text: longer queries | 1462 | 1449 | Grok 4.5 |
| LMArena Text: writing and language | 1445 | 1425 | Grok 4.5 |
| LMArena Text: entertainment and media | 1434 | 1412 | Grok 4.5 |
| LMArena Vision: English | 1285 | 1290 | Step 5 Preview |
| LMArena Vision: Chinese | 1345 | Not measured | Only Grok 4.5 measured |
| LMArena Vision: reading text | 1293 | 1282 | Grok 4.5 |
| LMArena Vision: humor | 1276 | Not measured | Only Grok 4.5 measured |
| LMArena Vision: creative writing | 1293 | Not measured | Only Grok 4.5 measured |
| LMArena Document | 1452 | Not measured | Only Grok 4.5 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 | Grok 4.5 | 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 | SpaceXAI Grok 4.5 | StepFun Step 5 Preview |
|---|---|---|
| Maker | xAI | StepFun |
| Weights | No public weights listed | Open weights |
| Released | July 8, 2026 | October 8, 2026 |
| Context window | 500K | 1.05M |
| Input $/Mtok | $2.00 | $1.00 |
| Output $/Mtok | $6.00 | $2.70 |
| Coding index | 58.6 | 61.1 |
| Independent measurements behind it | 6 | 4 |
| Cost per solved task | $0.62 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Grok 4.5 better than Step 5 Preview for coding?
Pick Step 5 Preview for coding: it scores 61.1 on the Vibe Coding Index against 58.6 for Grok 4.5, though on 4 benchmarks against 6. Pick Grok 4.5 for work measured by LiveBench coding or IOI (Vals AI), where it leads.
Which is cheaper, Grok 4.5 or Step 5 Preview?
Grok 4.5 costs $2.00 per million input tokens and $6.00 per million output tokens; Step 5 Preview costs $1.00 and $2.70. Cost per solved task is known for Grok 4.5 only.
Which has the bigger context window, Grok 4.5 or Step 5 Preview?
Step 5 Preview, with 1.05M tokens against 500K.
How many benchmarks is the Grok 4.5 vs Step 5 Preview comparison based on?
55 benchmarks have a result for both models as of October 22, 2026. Grok 4.5's coding index rests on 6 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.