AI model comparison
Step 5 Preview vs Claude Sonnet 5.5
Pricing, context window, benchmarks, and features compared side by side. Or skip the guesswork and send one prompt to both.
StepFun
Step 5 Preview
Step 5 Preview is StepFun's flagship model for agentic work, built on a sparse Mixture-of-Experts architecture (27B active / 600B total parameters).
- Input / 1M
- $1
- Output / 1M
- $2.70
- Context
- 1M
Anthropic
Claude Sonnet 5.5
Claude Sonnet 5.5 is Anthropic's Sonnet-class model for well-scoped everyday work, succeeding Claude Sonnet 5 as a direct upgrade.
- Input / 1M
- $2
- Output / 1M
- $10
- Context
- 1M
At a glance
Quick verdict
How the two models stack up on the things people ask about most.
Lower price
Step 5 Preview
2.7x cheaper for a typical chat
Higher intelligence score
Tie
Not enough benchmark data
Larger context window
Tie
1M vs 1M tokens
Newer release
Step 5 Preview
Released October 8, 2026
Benchmarks
Benchmark scores
Independent scores from Artificial Analysis. Higher is better.
Intelligence index
Claude Sonnet 5.556Coding index
Claude Sonnet 5.5Not availableAgentic index
Claude Sonnet 5.5Not availablePricing
Step 5 Preview vs Claude Sonnet 5.5 API pricing
Per-token API rates. Cheaper option highlighted.
| Metric | Claude Sonnet 5.5 | |
|---|---|---|
| Input tokensPer 1M tokens | $1 | $2 |
| Output tokensPer 1M tokens | $2.70 | $10 |
| Cached input (read)Per 1M tokens | $0.05 | $0.10 |
| Cache writePer 1M tokens | Not available | $2.50 |
| Web searchPer request | Not available | $0.01 |
What it costs in practice
Estimated cost per 1,000 requests at standard rates. Coding and long-document figures also show the cost when the input is already cached.
Chat message
2K in, 500 out
Claude Sonnet 5.5$9Coding task
30K in, 4K out
Claude Sonnet 5.5$100$43 cachedLong document summary
150K in, 2K out
Claude Sonnet 5.5$320$35 cachedSpecs
Context window and capabilities
How much each model can read, how much it can write, and what it accepts as input.
| Metric | Claude Sonnet 5.5 | |
|---|---|---|
| Context window | 1M tokens | 1M tokens |
| Max output | 64K tokens | 128K tokens |
| Input types | Image, Text, Video | File, Image, Text |
| Output types | Text | Text |
| Reasoning effort levels | High, Medium, Low | Max, Extra high, High, Medium, Low |
| Default reasoning effort | Medium | High |
| Release date | October 8, 2026 | September 28, 2026 |
Features
Supported features
API features available for each model.
| Metric | Claude Sonnet 5.5 | |
|---|---|---|
| Tool calling | Supported | Supported |
| Structured outputs | Supported | Supported |
| JSON mode | Supported | Supported |
| Reasoning | Supported | Supported |
| Temperature | Supported | Not supported |
| Stop sequences | Supported | Supported |
| Deterministic seed | Not supported | Not supported |
| Verbosity control | Not supported | Supported |
Keep exploring
More on these models
Other head-to-heads, the full model page, and the alternatives list for each model.
- Step 5 Preview vs DeepSeek V4.1 Flash
- Step 5 Preview vs GLM 5.3 Flash
- Step 5 Preview vs MiMo-V2.6-Flash
- Step 5 Preview vs Hy4 preview
- Step 5 Preview vs GPT-6 Luna
- Step 5 Preview vs DeepSeek V4 Flash 0731
- Step 5 Preview vs Claude Opus 5.5
- Step 5 Preview vs GLM 5.3
- Step 5 Preview vs DeepSeek V4 Flash 0423
- Step 5 Preview vs Hy3
- Step 5 Preview vs Gemini 3.8 Flash
- Step 5 Preview vs GPT-6.1 Sol
- Step 5 Preview vs DeepSeek V4 Pro 0813
- Step 5 Preview vs Gemini 3 Flash Preview
- Step 5 Preview vs Claude Opus 5
- Step 5 Preview vs GPT-6 Astra
- Step 5 Preview vs Qwen3.8 27B
- Step 5 Preview vs Gemini 2.5 Flash
- Step 5 Preview vs Claude Fable 5.1
- Step 5 Preview vs GLM 5.3 FlashX
- Step 5 Preview vs GPT-5.6 Luna Pro
Claude Sonnet 5.5View full model details- Claude Sonnet 5.5 vs Claude Opus 5.5
- Claude Sonnet 5.5 vs Claude Fable 5.1
- Claude Sonnet 5.5 vs GPT-6 Astra
- Claude Sonnet 5.5 vs GPT-6.1 Sol
- Claude Sonnet 5.5 vs Claude Opus 5
- Claude Sonnet 5.5 vs Claude Fable 5
- Claude Sonnet 5.5 vs Muse Spark 1.3
- Claude Sonnet 5.5 vs GPT-6 Sol
- Claude Sonnet 5.5 vs GPT-5.6 Sol
- Claude Sonnet 5.5 vs DeepSeek V4.1 Flash
- Claude Sonnet 5.5 vs GLM 5.3 Flash
- Claude Sonnet 5.5 vs MiMo-V2.6-Flash
- Claude Sonnet 5.5 vs GLM 5.3
- Claude Sonnet 5.5 vs Hy4 preview
- Claude Sonnet 5.5 vs Kimi K3
- Claude Sonnet 5.5 vs GPT-6 Luna
- Claude Sonnet 5.5 vs DeepSeek V4 Flash 0731
- Claude Sonnet 5.5 vs DeepSeek V4 Flash 0423
- Claude Sonnet 5.5 vs Hy3
Our take
Step 5 Preview is 2.7x cheaper for a typical chat. The right pick depends on your workload, so the quickest way to settle it is to send the same prompt to both and compare.
FAQ
Frequently asked questions
Is Step 5 Preview or Claude Sonnet 5.5 cheaper?
Step 5 Preview is cheaper for a typical chat (2K input tokens and 500 output tokens). Step 5 Preview costs $1 per 1M input tokens and $2.70 per 1M output tokens, while Claude Sonnet 5.5 costs $2 per 1M input tokens and $10 per 1M output tokens.
Which has a bigger context window, Step 5 Preview or Claude Sonnet 5.5?
Step 5 Preview supports up to 1M tokens of context, compared with 1M for Claude Sonnet 5.5.
Can I use Step 5 Preview and Claude Sonnet 5.5 at the same time?
Yes. Shortcut Chat sends one prompt to multiple models at once, so you can see Step 5 Preview and Claude Sonnet 5.5 answer side by side and keep the better response.
Why choose? Ask both.
Send one prompt to Step 5 Preview and Claude Sonnet 5.5 at the same time. Compare the answers side by side and keep the best one.