Claude Haiku 4.5 vs Step 3.5 Flash
Claude Haiku 4.5 (2025) and Step 3.5 Flash (2026) are frontier reasoning models from Anthropic and StepFun. Claude Haiku 4.5 ships a 200k-token context window, while Step 3.5 Flash ships a 256k-token context window. On SWE-bench Verified, Step 3.5 Flash leads by 1.1 pts. On pricing, Step 3.5 Flash costs $0.10/1M input tokens versus $0.80/1M for the alternative. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
Step 3.5 Flash is ~700% cheaper at $0.10/1M; pay for Claude Haiku 4.5 only for coding workflow support.
Decision scorecard
Local evidence first| Signal | Claude Haiku 4.5 | Step 3.5 Flash |
|---|---|---|
| Best for | multimodal apps, tool-calling agents, and provider-routed production | reasoning-heavy apps |
| Decision fit | Coding, RAG, and Agents | Coding, Agents, and Long context |
| Context window | 200k | 256k |
| Cheapest output | $4/1M tokens | $0.30/1M tokens |
| Provider routes | 9 tracked | 1 tracked |
| Shared benchmarks | 1 shared | SWE-bench Verified leader |
Decision tradeoffs
- Claude Haiku 4.5 has broader tracked provider coverage for fallback and route flexibility.
- Claude Haiku 4.5 uniquely exposes Vision, Multimodal, and JSON / Tool use in local model data.
- Local decision data tags Claude Haiku 4.5 for Coding, RAG, and Agents.
- Step 3.5 Flash holds a shared-benchmark lead on SWE-bench Verified, ahead by 1.1 points.
- Step 3.5 Flash has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Step 3.5 Flash has the lower cheapest tracked output price at $0.30/1M tokens.
- Step 3.5 Flash uniquely exposes Reasoning in local model data.
- Local decision data tags Step 3.5 Flash for Coding, Agents, and Long context.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Claude Haiku 4.5
$1,640
Cheapest tracked route/tier: AWS Bedrock
Step 3.5 Flash
$155
Cheapest tracked route/tier: OpenRouter
Estimated monthly gap: $1,485. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- Step 3.5 Flash is $3.70/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Vision, Multimodal, and JSON / Tool use before moving production traffic.
- Step 3.5 Flash adds Reasoning in local capability data.
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- Claude Haiku 4.5 is $3.70/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Check replacement coverage for Reasoning before moving production traffic.
- Claude Haiku 4.5 adds Vision, Multimodal, and JSON / Tool use in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-10-01 | 2026-01-29 |
| Context window | 200k | 256k |
| Parameters | — | 196B (11B active) |
| Architecture | Decoder Only | Mixture of Experts |
| License | Proprietary | Proprietary |
| Openness | Proprietary | Proprietary |
| Weights | Not released | Not released |
| Code | Unknown | Unknown |
| Commercial use | Commercial use: conditional | Commercial use: conditional |
| Knowledge cutoff | 2025-02 | - |
Pricing and availability
| Pricing attribute | Claude Haiku 4.5 | Step 3.5 Flash |
|---|---|---|
| Input price | $0.80/1M tokens | $0.10/1M tokens |
| Output price | $4/1M tokens | $0.30/1M tokens |
| Providers |
Capabilities
| Capability | Claude Haiku 4.5 | Step 3.5 Flash |
|---|---|---|
| Vision | Yes | No |
| Multimodal | Yes | No |
| Reasoning | No | Yes |
| JSON / Tool use | Yes | No |
| Structured outputs | Yes | No |
| Code execution | Yes | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | Claude Haiku 4.5 | Step 3.5 Flash |
|---|---|---|
| SWE-bench Verified | 73.3 | 74.4 |
Continue comparing
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Last reviewed: 2026-07-26. Data sourced from public model cards and provider documentation.