Which is better for coding — GPT-5.1 Medium or Step-3.5-Flash?

Direct comparison on the SWE-Bench benchmark is not available. We recommend reviewing other metrics on the comparison page.

Which model is cheaper — GPT-5.1 Medium or Step-3.5-Flash?

Step-3.5-Flash is cheaper for input: $0.10 per 1M tokens vs $1.00.

Which has a larger context window — GPT-5.1 Medium or Step-3.5-Flash?

GPT-5.1 Medium supports a larger context: 256,000 tokens vs 65,536.

GPT-5.1 Medium vs Step-3.5-Flash: Specs & Benchmark Comparison

Characteristic	GPT-5.1 Medium	Step-3.5-Flash
Company	OpenAI	StepFun
Release Date	November 11, 2025	February 1, 2026
Parameters	—	196B
Multimodal	Yes	Yes
Context (input)	256K	66K
Context (output)	64K	8K
Input Price / 1M	$1.00	$0.10
Output Price / 1M	$4.00	$0.40
Average Score	1.0	0.8
Benchmarks
AIME 2025	1.0	1.0

Visual Benchmark Comparison

GPT-5.1 Medium

Step-3.5-Flash

AIME 20251.0 vs 1.0

1.0

Verdict

Step-3.5-Flash leads in 2 out of 4 comparison categories.

Overall Performance

Both models show comparable average scores: GPT-5.1 Medium — 1.0, Step-3.5-Flash — 0.8.

API Cost

Step-3.5-Flash is 10.0x cheaper: input $0.10/1M vs $1.00/1M tokens.

Context Window

GPT-5.1 Medium supports a larger context: 256K vs 66K tokens.

Recency

Step-3.5-Flash is newer: released 2/1/2026 vs 11/11/2025.

More About These Models

GPT-5.1 Medium

OpenAI — specs, benchmarks, API

Step-3.5-Flash

StepFun — specs, benchmarks, API

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GPT-5.1 Medium vs GPT-5.2 GPT-5.1 Codex High vs GPT-5.1 Medium GPT-5.1 High vs GPT-5.1 Medium GPT-5.1 Medium vs GPT-5.4 GPT-5 High vs GPT-5.1 Medium GPT-5.1 Medium vs GPT-5.1 Thinking

All model comparisons →

The GPT-5.1 Medium and Step-3.5-Flash comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the GPT-5.1 Medium or Step-3.5-Flash page. See also the complete list of AI model comparisons.