Compare / head-to-head
Claude Opus 4.8vsStep 3.5 Flash
Claude Opus 4.8 leads 4 of 4 shared benchmarks. Claude Opus 4.8 has the larger context window (1M tokens).
Benchmarks from cited public sources; pricing from official pages; status from official provider feeds.
Shared benchmarks
4 – 0
Claude Opus 4.8 leads
Cheaper per token
—
list price, input + output
Larger context
Claude Opus 4.8
1M tokens
Provider uptime (30d)
100% · —
Anthropic · StepFun
Claude Opus 4.8
Anthropic · released 2026-05-28
textvision
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
4 shared · 12 only Claude Opus 4.8 · 13 only Step 3.5 Flash| Benchmark | Claude Opus 4.8 | Step 3.5 Flash | Δ | Edge |
|---|---|---|---|---|
| Reported by both · 4 | ||||
| SWE-bench Verified | 88.6% ↗ | 74.4% ↗ | +14.2 pt | Claude Opus 4.8 |
| AIME 2026 | 100% ↗matharena ⚠ | 96.7% ↗matharena | +3.3 pt | Claude Opus 4.8 |
| LMArena Elo | 1452.7 ↗ | 1403.7 ↗ | +49 | Claude Opus 4.8 |
| BrowseComp | 84.3% ↗ | 51.6% ↗ | +32.7 pt | Claude Opus 4.8 |
| Only Claude Opus 4.8 reports · 12 | ||||
| GPQA Diamond | 93.6% ↗ | not reported | — | — |
| Humanity's Last Exam (no tools) | 49.8% ↗ | not reported | — | — |
| FrontierMath Tier 4 v2 (Epoch AI run) | 56.1% ↗epoch | not reported | — | — |
| FrontierMath Tiers 1-3 v2 (Epoch AI run) | 80% ↗epoch | not reported | — | — |
| Humanity's Last Exam (with tools) | 57.9% ↗ | not reported | — | — |
| OSWorld-Verified | 83.4% ↗ | not reported | — | — |
| OTIS Mock AIME 2024-2025 (Epoch AI run) | 98.3% ↗epoch | not reported | — | — |
| SimpleQA Verified | 53% ↗epoch | not reported | — | — |
| SWE-bench Multilingual | 84.4% ↗ | not reported | — | — |
| SWE-bench Multimodal | 38.4% ↗ | not reported | — | — |
| SWE-Bench Pro | 69.2% ↗ | not reported | — | — |
| Terminal-Bench 2.1 | 74.6% ↗ | not reported | — | — |
| Only Step 3.5 Flash reports · 13 | ||||
| AIME 2025 | not reported | 97.3% ↗ | — | — |
| BrowseComp (with context manager) | not reported | 69% ↗ | — | — |
| BrowseComp-ZH | not reported | 66.9% ↗ | — | — |
| BrowseComp-ZH (with context manager) | not reported | 73.7% ↗ | — | — |
| GAIA (no file) | not reported | 84.5% ↗ | — | — |
| HMMT 2025 (Feb/Nov average) | not reported | 96.2% ↗ | — | — |
| IMOAnswerBench | not reported | 85.4% ↗ | — | — |
| LiveCodeBench v6 | not reported | 86.4% ↗ | — | — |
| ResearchRubrics | not reported | 65.3% ↗ | — | — |
| Tau2-Bench | not reported | 88.2% ↗ | — | — |
| Terminal-Bench 2.0 | not reported | 51% ↗ | — | — |
| xbench-DeepSearch 2025.05 | not reported | 83.7% ↗ | — | — |
| xbench-DeepSearch 2025.10 | not reported | 56.3% ↗ | — | — |
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 4.8 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
Official pricing pages and model cards| Spec | Claude Opus 4.8 | Step 3.5 Flash | Edge |
|---|---|---|---|
| Context window | 1M tokens | 256K tokens | Claude Opus 4.8 |
| Max output | 128K tokens | — | — |
| Input price / 1M | $5 ↗ | — | — |
| Output price / 1M | $25 ↗ | — | — |
| Cached input / 1M | $0.5 ↗ | — | — |
| Input + output / 1M Lower is cheaper. List prices; batch, tool and regional fees excluded. | $30 | — | — |
| Modalities | text · vision | text | Claude Opus 4.8 |
| Released | 2026-05-28 | 2026-02-12 | — |
| Cited benchmark scores | 17 | 18 | — |
Reliability
Provider status
Last 60 days · refreshed daily on this page · live on /statusMore matchups
Claude Opus 4.8 vs …
Models sharing the most benchmarksMore matchups
Step 3.5 Flash vs …
Models sharing the most benchmarksBuilt by Respan
Which one wins on your data?
Public benchmarks are a starting point. Run Claude Opus 4.8 and Step 3.5 Flash on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.