Claude Opus 4.8 (Fast) vs Step 3.7 Flash

Compare Claude Opus 4.8 (Fast) from Anthropic and Step 3.7 Flash from stepfun on key metrics including benchmarks, price, context length, and other model features. Access both models and hundreds of others through the OpenRouter API.

Claude Opus 4.8 (Fast) vs Step 3.7 Flash: side-by-side summary

Claude Opus 4.8 (Fast) and Step 3.7 Flash are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.

Claude Opus 4.8 (Fast), from Anthropic, has a 1,000,000-token context window and is priced by the provider serving it on OpenRouter.

Step 3.7 Flash, from stepfun, has a 262,144-token context window and is priced at $0.20/M tokens input, $1.15/M tokens output on OpenRouter.

Context window

Claude Opus 4.8 (Fast): 1,000,000 tokens
Step 3.7 Flash: 262,144 tokens

Price

Claude Opus 4.8 (Fast): Pricing varies by provider
Step 3.7 Flash: $0.20/M tokens input, $1.15/M tokens output

Provided by

Claude Opus 4.8 (Fast): Anthropic
Step 3.7 Flash: stepfun

Claude Opus 4.8 (Fast) vs Step 3.7 Flash at a glance

Claude Opus 4.8 (Fast) vs Step 3.7 Flash comparison
Attribute	Claude Opus 4.8 (Fast)	Step 3.7 Flash
Input price	Pricing varies by provider	$0.20/M tokens
Output price	Pricing varies by provider	$1.15/M tokens
Context window	1,000,000 tokens	262,144 tokens
Intelligence Index	Not available	19.5
Coding Index	Not available	39.6
Agentic Index	Not available	Not available
Latency (p50)	Not available	4.14 s
Throughput (p50)	Not available	51.0 tok/s

Benchmark data updated Oct 13, 2026

Frequently asked questions

Which has the longer context window, Claude Opus 4.8 (Fast) or Step 3.7 Flash?

Claude Opus 4.8 (Fast) has the longer context window at 1,000,000 tokens, compared with 262,144 tokens for Step 3.7 Flash.

Claude Opus 4.8 (Fast) vs Step 3.7 Flash

Claude Opus 4.8 (Fast) vs Step 3.7 Flash

Overview