Claude Haiku 5.5 vs Step 5 Preview
Claude Haiku 5.5 leads Step 5 Preview on coding, 70.7 to 61.1 on the Vibe Coding Index, and Claude Haiku 5.5 costs 5.4x less per output token ($0.50 vs $2.70 per million). Updated October 22, 2026; 30 benchmarks have a result for both.
Claude Haiku 5.5 or Step 5 Preview: which to pick
Pick Claude Haiku 5.5 for coding: it scores 70.7 on the Vibe Coding Index against 61.1 for Step 5 Preview.
Pick Step 5 Preview for a larger context window (1.05M against 1M tokens) and work measured by SciCode or AA Intelligence Index, where it leads.
- Shared results
- 30
- Claude Haiku 5.5 only
- 33
- Step 5 Preview only
- 31
- Like-for-like categories
- 7 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 Haiku 5.5
Claude Haiku 5.5 scores 70.7 against 61.1.
5 and 4 benchmarks behind the scores
Intelligence
AA Intelligence Index
Step 5 Preview
Step 5 Preview leads, 43.7 against 43.4.
Same board, both measured
Web design
Design Arena: websites
No call
Only Claude Haiku 5.5 has a Design Arena: websites result, 1262.
Directional only
General
Vals Index
No call
Only Claude Haiku 5.5 has a Vals Index result, 58.7%.
Directional only
Long documents
Listed context window
Step 5 Preview
Step 5 Preview takes 1.05M tokens against 1M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Claude Haiku 5.5
Claude Haiku 5.5 $0.0003, Step 5 Preview $0.0024 per turn.
List prices
At a glance
- Coding index
- Claude Haiku 5.5 70.7 from 5 benchmarks, Step 5 Preview 61.1 from 4 benchmarks.
- Widest category
- Math, 47.0 points apart on average over 1 shared benchmark.
- Widest single gap
- LiveBench browser: Claude Haiku 5.5 80.0% against Step 5 Preview 24.0%, 56.0 points apart on a 0 to 100 scale.
- Output price
- Claude Haiku 5.5 $0.50 against Step 5 Preview $2.70 per million output tokens, 5.4x apart.
- Context window
- Claude Haiku 5.5 takes 1M 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 | Claude Haiku 5.5 | Bars | Step 5 Preview | Ties |
|---|---|---|---|---|
| Coding | 9 | 1 | ||
| Intelligence | 0 | 1 | ||
| Agentic work | 11 | 0 | ||
| Reasoning | 1 | 2 | ||
| Math | 1 | 0 | ||
| Web design | 1 | 0 | ||
| General | 1 | 2 | ||
| All shared boards | 24 | 6 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index91
| Benchmark | Claude Haiku 5.5 | Step 5 Preview | Leader |
|---|---|---|---|
| LiveBench coding | 91.4% | 85.6% | Claude Haiku 5.5 |
| LMArena WebDev | 1586 | 1567 | Claude Haiku 5.5 |
| Terminal-Bench 4 (Vals AI) | 36.4% | 31.8% | Claude Haiku 5.5 |
| Vibe Code Bench (Vals AI) | 90.4% | 70.4% | Claude Haiku 5.5 |
| Code migration (Vals AI) | 44.6% | 39.0% | Claude Haiku 5.5 |
| ProgramBench (Vals AI) | 2.5% | Not measured | Only Claude Haiku 5.5 measured |
| IOI (Vals AI) | 47.3% | 38.1% | Claude Haiku 5.5 |
| SWE-bench Multimodal (Vals AI) | 44.0% | 40.8% | Claude Haiku 5.5 |
| Vibe Code Bench 1-100 (Vals AI) | 20.4% | Not measured | Only Claude Haiku 5.5 measured |
| CyberBench (Vals AI) | 75.5% | Not measured | Only Claude Haiku 5.5 measured |
| SciCode | 55.0% | 58.9% | Step 5 Preview |
| FrontierCode | 46.4% | Not measured | Only Claude Haiku 5.5 measured |
| FrontierSWE | 43.8% | Not measured | Only Claude Haiku 5.5 measured |
| LMArena Text: coding | Not measured | 1485 | Only Step 5 Preview measured |
| LMArena Text: software and IT | Not measured | 1473 | Only Step 5 Preview measured |
| LMArena WebDev: React | 1605 | 1583 | Claude Haiku 5.5 |
| LMArena WebDev: HTML | 1569 | 1556 | Claude Haiku 5.5 |
| LMArena WebDev: from an image | Not measured | 1550 | Only Step 5 Preview measured |
| SciCode | 9.2% | Not measured | Only Claude Haiku 5.5 measured |
| Neither model has a result on the other 20 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Claude Haiku 5.5 | Step 5 Preview | Leader |
|---|---|---|---|
| AA Intelligence Index | 43.4 | 43.7 | Step 5 Preview |
| Epoch Capabilities Index | 159.3 | Not measured | Only Claude Haiku 5.5 measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index110
| Benchmark | Claude Haiku 5.5 | Step 5 Preview | Leader |
|---|---|---|---|
| LiveBench research | 81.9% | 72.8% | Claude Haiku 5.5 |
| LiveBench browser | 80.0% | 24.0% | Claude Haiku 5.5 |
| LiveBench long agentic | 57.6% | 27.5% | Claude Haiku 5.5 |
| SREBench (Vals AI) | 5.7% | 0.4% | Claude Haiku 5.5 |
| Finance Agent (Vals AI) | 54.1% | 50.7% | Claude Haiku 5.5 |
| Tax Agent Bench (Vals AI) | 31.9% | 27.3% | Claude Haiku 5.5 |
| Legal Research Bench (Vals AI) | 43.3% | 40.4% | Claude Haiku 5.5 |
| Harvey's Legal Agent Benchmark (Vals AI) | 4.2% | Not measured | Only Claude Haiku 5.5 measured |
| Excel Modeling Benchmark (Vals AI) | 59.0% | 57.1% | Claude Haiku 5.5 |
| BioMysteryBench (Vals AI) | 70.4% | 67.4% | Claude Haiku 5.5 |
| Terminal-Bench-Science (Vals AI) | 10.0% | 2.9% | Claude Haiku 5.5 |
| Vals Science Index | 38.5% | 29.6% | Claude Haiku 5.5 |
| APEX-Agents | 56.1% | Not measured | Only Claude Haiku 5.5 measured |
| Vending-Bench 2 | $3,602 | Not measured | Only Claude Haiku 5.5 measured |
| Neither model has a result on the other 27 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index12
| Benchmark | Claude Haiku 5.5 | Step 5 Preview | Leader |
|---|---|---|---|
| LiveBench reasoning | 82.4% | 83.8% | Step 5 Preview |
| MysteryMechanism (Vals AI) | 35.1% | 18.5% | Claude Haiku 5.5 |
| Humanity's Last Exam (Artificial Analysis run) | 44.4% | 46.5% | Step 5 Preview |
| GPQA Diamond (Epoch AI run) | 89.6% | Not measured | Only Claude Haiku 5.5 measured |
| ARC-AGI | 89.0% | Not measured | Only Claude Haiku 5.5 measured |
| ARC-AGI-2 | 61.3% | Not measured | Only Claude Haiku 5.5 measured |
| Chess puzzles | 55.0% | Not measured | Only Claude Haiku 5.5 measured |
| Mystery game puzzles | 30.0% | Not measured | Only Claude Haiku 5.5 measured |
| EBR-bench | 43.8% | Not measured | Only Claude Haiku 5.5 measured |
| LMArena Text: hard prompts | Not measured | 1461 | Only Step 5 Preview measured |
| LMArena Text: expert | Not measured | 1485 | Only Step 5 Preview measured |
| LMArena Text: hard prompts in English | Not measured | 1454 | Only Step 5 Preview measured |
| LMArena Vision: diagrams | Not measured | 1308 | Only Step 5 Preview measured |
| LMArena Vision: homework | Not measured | 1265 | Only Step 5 Preview measured |
| Neither model has a result on the other 8 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Claude Haiku 5.5 | Step 5 Preview | Leader |
|---|---|---|---|
| OTIS Mock AIME | 98.9% | Not measured | Only Claude Haiku 5.5 measured |
| FrontierMath, tiers 1 to 3 | 75.1% | Not measured | Only Claude Haiku 5.5 measured |
| FrontierMath, tier 4 | 46.3% | Not measured | Only Claude Haiku 5.5 measured |
| ProofBench | 89.0% | 42.0% | Claude Haiku 5.5 |
| LMArena Text: math | Not measured | 1458 | Only Step 5 Preview measured |
| LMArena Text: mathematical work | Not measured | 1460 | Only Step 5 Preview measured |
| Neither model has a result on the other 7 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index6 boards, none shared
| Benchmark | Claude Haiku 5.5 | Step 5 Preview | Leader |
|---|---|---|---|
| MedCode (Vals AI) | 51.5% | Not measured | Only Claude Haiku 5.5 measured |
| SimpleQA Verified | 23.8% | Not measured | Only Claude Haiku 5.5 measured |
| LMArena Text: science | Not measured | 1454 | Only Step 5 Preview measured |
| LMArena Text: medicine and healthcare | Not measured | 1439 | Only Step 5 Preview measured |
| LMArena Text: legal and government | Not measured | 1437 | Only Step 5 Preview measured |
| LMArena Text: business and finance | Not measured | 1435 | Only Step 5 Preview measured |
| Neither model has a result on the other 12 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Claude Haiku 5.5 | Step 5 Preview | Leader |
|---|---|---|---|
| Design Arena: websites | 1262 | Not measured | Only Claude Haiku 5.5 measured |
| Design Arena: UI components | 1291 | Not measured | Only Claude Haiku 5.5 measured |
| Design Arena: game dev | 1313 | Not measured | Only Claude Haiku 5.5 measured |
| Design Arena: data viz | 1294 | Not measured | Only Claude Haiku 5.5 measured |
| Design Arena: 3D | 1342 | Not measured | Only Claude Haiku 5.5 measured |
| Design Arena: all code categories | 1278 | Not measured | Only Claude Haiku 5.5 measured |
| LiveBench design | 83.1% | 76.9% | Claude Haiku 5.5 |
| Neither model has a result on the other 2 boards here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index12
| Benchmark | Claude Haiku 5.5 | Step 5 Preview | Leader |
|---|---|---|---|
| Vals Index | 58.7% | Not measured | Only Claude Haiku 5.5 measured |
| LiveBench data analysis | 53.1% | 63.5% | Step 5 Preview |
| Public Benefits Bench (Vals AI) | 63.2% | 58.1% | Claude Haiku 5.5 |
| SAGE (Vals AI) | 45.8% | Not measured | Only Claude Haiku 5.5 measured |
| MedScribe (Vals AI) | 89.5% | Not measured | Only Claude Haiku 5.5 measured |
| Long context reasoning (AA-LCR) | 82.7% | 88.3% | Step 5 Preview |
| DTBench | 95.0% | Not measured | Only Claude Haiku 5.5 measured |
| LMCA | 51.1% | Not measured | Only Claude Haiku 5.5 measured |
| Furniture assembly | 47.5% | Not measured | Only Claude Haiku 5.5 measured |
| LMArena Text | Not measured | 1440 | Only Step 5 Preview measured |
| LMArena Text: instruction following | Not measured | 1438 | Only Step 5 Preview measured |
| LMArena Text: creative writing | Not measured | 1409 | Only Step 5 Preview measured |
| LMArena Vision | Not measured | 1265 | Only Step 5 Preview measured |
| LMArena Text: English | Not measured | 1447 | Only Step 5 Preview measured |
| LMArena Text: non-English | Not measured | 1428 | Only Step 5 Preview measured |
| LMArena Text: Chinese | Not measured | 1500 | Only Step 5 Preview measured |
| LMArena Text: Japanese | Not measured | 1383 | Only Step 5 Preview measured |
| LMArena Text: French | Not measured | 1438 | Only Step 5 Preview measured |
| LMArena Text: Spanish | Not measured | 1441 | Only Step 5 Preview measured |
| LMArena Text: Russian | Not measured | 1433 | Only Step 5 Preview measured |
| LMArena Text: multi-turn | Not measured | 1437 | Only Step 5 Preview measured |
| LMArena Text: longer queries | Not measured | 1449 | Only Step 5 Preview measured |
| LMArena Text: writing and language | Not measured | 1425 | Only Step 5 Preview measured |
| LMArena Text: entertainment and media | Not measured | 1412 | Only Step 5 Preview measured |
| LMArena Vision: English | Not measured | 1290 | Only Step 5 Preview measured |
| LMArena Vision: reading text | Not measured | 1282 | Only Step 5 Preview measured |
| Neither model has a result on the other 20 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Claude Haiku 5.5 | 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
Claude Haiku 5.5 costs less
Repository review
50K input + 3K output tokens
Claude Haiku 5.5 costs less
Agent loop
200K input + 10K output tokens
Claude Haiku 5.5 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 Haiku 5.5 | StepFun Step 5 Preview |
|---|---|---|
| Maker | Anthropic | StepFun |
| Weights | No public weights listed | Open weights |
| Released | October 7, 2026 | October 8, 2026 |
| Context window | 1M | 1.05M |
| Input $/Mtok | $0.10 | $1.00 |
| Output $/Mtok | $0.50 | $2.70 |
| Coding index | 70.7 | 61.1 |
| Independent measurements behind it | 5 | 4 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Haiku 5.5 better than Step 5 Preview for coding?
Pick Claude Haiku 5.5 for coding: it scores 70.7 on the Vibe Coding Index against 61.1 for Step 5 Preview. Pick Step 5 Preview for a larger context window (1.05M against 1M tokens) and work measured by SciCode or AA Intelligence Index, where it leads.
Which is cheaper, Claude Haiku 5.5 or Step 5 Preview?
Claude Haiku 5.5 costs $0.10 per million input tokens and $0.50 per million output tokens; Step 5 Preview costs $1.00 and $2.70. Cost per solved task is known for neither of them.
Which has the bigger context window, Claude Haiku 5.5 or Step 5 Preview?
Step 5 Preview, with 1.05M tokens against 1M.
How many benchmarks is the Claude Haiku 5.5 vs Step 5 Preview comparison based on?
30 benchmarks have a result for both models as of October 22, 2026. Claude Haiku 5.5's coding index rests on 5 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.