API cost decision in 10 seconds

Step 3.5 Flash vs NewClaude Opus 4.7 (Fast)

Pick Step 3.5 Flash for lower cost; pick Claude Opus 4.7 (Fast) only if the larger context window matters more.

Page updated: 2026-05-26T15:08:08Z Data confirmed: 2026-05-26T18:08:02Z Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick Step 3.5 Flash for lower cost; pick Claude Opus 4.7 (Fast) only if the larger context window matters more.

On the standard 1M input plus 500K output workload, Step 3.5 Flash is estimated at $0.24 vs $105 for Claude Opus 4.7 (Fast), saving $104.76 (99.8% lower).

Cost-first pickStep 3.5 Flash

Context-first pickClaude Opus 4.7 (Fast)

Sample savings$104.7699.8%

10x traffic gap$1047.6

Claude Opus 4.7 (Fast) has more context, but Step 3.5 Flash saves $104.76 on the standard workload. At 10x that traffic, the same price gap is about $1047.6. Use the calculator below to replace the sample workload with your own token volume.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

Step 3.5 Flash stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shape	Token mix	Better pick	Step 3.5 Flash	Claude Opus 4.7 (Fast)
Input-heavy / RAG	5M input + 500K output	Step 3.5 Flash	$0.6	$225
Balanced workload	1M input + 1M output	Step 3.5 Flash	$0.39	$180
Output-heavy chatbot	1M input + 5M output	Step 3.5 Flash	$1.59	$780

Cheaper input Step 3.5 Flash $0.09 vs $30 / 1M

Step 3.5 Flash is $29.91 cheaper per 1M input tokens (99.7% lower; 333.3x difference).

Cheaper output Step 3.5 Flash $0.3 vs $150 / 1M

Step 3.5 Flash is $149.7 cheaper per 1M output tokens (99.8% lower; 500x difference).

Larger context Claude Opus 4.7 (Fast) 262.14K vs 1M

Claude Opus 4.7 (Fast) has 737.86K more context (3.81x larger).

Sample workload Step 3.5 Flash $0.24 vs $105

Step 3.5 Flash is $104.76 cheaper on the standard workload (99.8% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.

Monthly input tokens Monthly output tokens

Step 3.5 Flash Calculating… Estimated API cost

Claude Opus 4.7 (Fast) Calculating… Estimated API cost

Cheaper for this workload Calculating… Difference: calculating…

This estimate uses normalized public API pricing per 1M tokens. It is a planning aid, not a billing quote. Verify provider pricing, limits, and terms before production use.

Quick Decision

Verdict

Step 3.5 Flash has the lower input price; Step 3.5 Flash has the lower output price; Claude Opus 4.7 (Fast) offers the larger context window. For the 1M input plus 500K output sample, Step 3.5 Flash is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $0.24 for Step 3.5 Flash and $105 for Claude Opus 4.7 (Fast).

Best Fit

Choose Step 3.5 Flash when you care most about lower input-token price, and lower output-token price.

Choose Claude Opus 4.7 (Fast) when you care most about larger context window.

Decision Notes

On the standard 1M input plus 500K output workload, Step 3.5 Flash is estimated at $0.24 vs $105 for Claude Opus 4.7 (Fast), saving $104.76 (99.8% lower).
Step 3.5 Flash is $104.76 cheaper on the standard workload (99.8% lower).
Step 3.5 Flash is $29.91 cheaper per 1M input tokens (99.7% lower; 333.3x difference).
Step 3.5 Flash is $149.7 cheaper per 1M output tokens (99.8% lower; 500x difference).
Claude Opus 4.7 (Fast) has 737.86K more context (3.81x larger).

Head-to-Head Specs

Feature	Step 3.5 Flash (StepFun)	NewClaude Opus 4.7 (Fast) (Anthropic)
Input Price prompt tokens per 1M	$0.09	$30
Completion Price per 1M tokens	$0.3	$150
Sample Workload Cost 1M input + 500K output	$0.24	$105
Context Window	262.14K	1M
Release Date	2026-01-29	2026-05-12
Popularity	#43	#112

Use-Case Decision Matrix

Use case	Better pick	Why
Budget-constrained production	Step 3.5 Flash	On the standard 1M input plus 500K output workload, Step 3.5 Flash is estimated at $0.24 vs $105 for Claude Opus 4.7 (Fast), saving $104.76 (99.8% lower).
High-volume input processing	Step 3.5 Flash	Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbots	Step 3.5 Flash	Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document work	Claude Opus 4.7 (Fast)	A larger context window leaves more room for retrieved passages, conversation history, or source files.

Related Alternatives

Same-provider lower-cost swaps

Claude 3 Haiku can replace Claude Opus 4.7 (Fast) when lower sample workload cost matters most: $0.88.
Claude 3.5 Haiku can replace Claude Opus 4.7 (Fast) when lower sample workload cost matters most: $2.8.
Anthropic Claude Haiku Latest can replace Claude Opus 4.7 (Fast) when lower sample workload cost matters most: $3.5.
Claude Haiku 4.5 can replace Claude Opus 4.7 (Fast) when lower sample workload cost matters most: $3.5.

Larger context near this budget

Llama 4 Scout offers 10M context with $0.23 sample workload cost.
Grok 4.20 offers 2M context with $2.5 sample workload cost.
Grok 4.20 Multi-Agent offers 2M context with $5 sample workload cost.
GPT-5.5 offers 1.05M context with $20 sample workload cost.

Popular competitors

DeepSeek V4 Flash · DeepSeek · #1
Hy3 preview · Tencent · #2
Claude Opus 4.7 · Anthropic · #3
Claude Sonnet 4.6 · Anthropic · #4

Cheaper alternatives

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Larger context alternatives

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Provider catalogs

Compare models within provider hubs before choosing a final API vendor.

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StepFun catalog

Review all tracked StepFun models before deciding whether this matchup is the right shortlist.

Open StepFun models

Anthropic catalog

Check other Anthropic models with comparable pricing, context, or release timing.

Open Anthropic models

Step 3.5 Flash

Step 3.5 Flash is StepFun's most capable open-source foundation model. Built on a sparse Mixture of Experts (MoE) architecture, it selectively activates only 11B of its 196B parameters per token....

Claude Opus 4.7 (Fast)

Fast-mode variant of [Opus 4.7](/anthropic/claude-opus-4.7) - identical capabilities with higher output speed at premium 6x pricing. Learn more in Anthropic's docs: https://platform.claude.com/docs/en/build-with-claude/fast-mode