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Claude Opus 4.1vsStep 3.5 Flash

Claude Opus 4.1 leads 1 of 1 shared benchmark. Step 3.5 Flash has the larger context window (256K tokens).

Benchmarks from cited public sources; pricing from official pages; status from official provider feeds.

Shared benchmarks
1 – 0
Claude Opus 4.1 leads
Cheaper per token
list price, input + output
Larger context
Step 3.5 Flash
256K tokens
Provider uptime (30d)
100% · —
Anthropic · StepFun
Claude Opus 4.1
Anthropic · released 2025-08-05
textvision
Context
200K
Max out
32K
Input /1M
$15
Output /1M
$75
Cached /1M
$1.5
Scores
6 · 6 core
Step 3.5 Flash
StepFun · released 2026-02-12
text
Context
256K
Max out
Input /1M
Output /1M
Cached /1M
Scores
18 · 5 core
Quality

Benchmark matrix

BenchmarkClaude Opus 4.1Step 3.5 FlashΔEdge
Reported by both · 1
SWE-bench Verified74.5% 74.4% +0.1 ptClaude Opus 4.1
Only Claude Opus 4.1 reports · 5
GPQA Diamond77.3% epochnot reported
FrontierMath Tier 4 v2 (Epoch AI run)2.4% epochnot reported
FrontierMath Tiers 1-3 v2 (Epoch AI run)12.6% epochnot reported
OTIS Mock AIME 2024-2025 (Epoch AI run)68.9% epochnot reported
SWE-bench Verified (Epoch AI run)73.3% epochnot reported
Only Step 3.5 Flash reports · 16
AIME 2025not reported97.3%
AIME 2026not reported96.7% matharena
LMArena Elonot reported1403.7
BrowseCompnot reported51.6%
BrowseComp (with context manager)not reported69%
BrowseComp-ZHnot reported66.9%
BrowseComp-ZH (with context manager)not reported73.7%
GAIA (no file)not reported84.5%
HMMT 2025 (Feb/Nov average)not reported96.2%
IMOAnswerBenchnot reported85.4%
LiveCodeBench v6not reported86.4%
ResearchRubricsnot reported65.3%
Tau2-Benchnot reported88.2%
Terminal-Bench 2.0not reported51%
xbench-DeepSearch 2025.05not reported83.7%
xbench-DeepSearch 2025.10not reported56.3%
Scores tagged "epoch" or "matharena" are independent runs, used only where the lab has not published its own; ⚠ marks rows MathArena flags as released after the competition. Higher is better on every row. Δ is Claude Opus 4.1 minus Step 3.5 Flash in the benchmark's own unit. "Not reported" means the lab has not published that figure; it is not a zero. ↗ opens the source.
Specs & pricing

Side by side

SpecClaude Opus 4.1Step 3.5 FlashEdge
Context window200K tokens256K tokensStep 3.5 Flash
Max output32K tokens
Input price / 1M$15
Output price / 1M$75
Cached input / 1M$1.5
Input + output / 1M
Lower is cheaper. List prices; batch, tool and regional fees excluded.
$90
Modalitiestext · visiontextClaude Opus 4.1
Released2025-08-052026-02-12
Cited benchmark scores618
Reliability

Provider status

All providers
More matchups

Claude Opus 4.1 vs …

More matchups

Step 3.5 Flash vs …

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Which one wins on your data?

Public benchmarks are a starting point. Run Claude Opus 4.1 and Step 3.5 Flash on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.