Compare / head-to-head
Solar Open 2 250B-A15BvsStep 3.5 Flash
Step 3.5 Flash leads 2 of 3 shared benchmarks. Solar Open 2 250B-A15B has the larger context window (1M tokens).
Benchmarks from cited public sources; pricing from official pages; status from official provider feeds.
Shared benchmarks
1 – 2
Step 3.5 Flash leads
Cheaper per token
—
list price, input + output
Larger context
Solar Open 2 250B-A15B
1M tokens
Provider uptime (30d)
— · —
Upstage · StepFun
Solar Open 2 250B-A15B
Upstage · released 2026-07-24
text
- Context
- 1M
- Max out
- —
- Input /1M
- —
- Output /1M
- —
- Cached /1M
- —
- Scores
- 16 · 5 core
Step 3.5 Flash
StepFun · released 2026-02-12
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- Context
- 256K
- Max out
- —
- Input /1M
- —
- Output /1M
- —
- Cached /1M
- —
- Scores
- 18 · 5 core
Quality
Benchmark matrix
3 shared · 13 only Solar Open 2 250B-A15B · 14 only Step 3.5 Flash| Benchmark | Solar Open 2 250B-A15B | Step 3.5 Flash | Δ | Edge |
|---|---|---|---|---|
| Reported by both · 3 | ||||
| SWE-bench Verified | 70.4% ↗ | 74.4% ↗ | -4 pt | Step 3.5 Flash |
| AIME 2026 | 95.7% ↗ | 96.7% ↗matharena | -1 pt | Step 3.5 Flash |
| LiveCodeBench v6 | 92.4% ↗ | 86.4% ↗ | +6 pt | Solar Open 2 250B-A15B |
| Only Solar Open 2 250B-A15B reports · 13 | ||||
| GPQA Diamond | 86.3% ↗ | not reported | — | — |
| MMLU-Pro | 86.2% ↗ | not reported | — | — |
| Humanity's Last Exam (no tools) | 28.8% ↗ | not reported | — | — |
| AA-LCR | 62.3% ↗ | not reported | — | — |
| APEX-Agents | 16.6% ↗ | not reported | — | — |
| ArtifactsBench | 55.9% ↗ | not reported | — | — |
| GDPval-AA v2 | 1128 ↗ | not reported | — | — |
| HMMT 2026-02 | 93.9% ↗ | not reported | — | — |
| IFBench | 80% ↗ | not reported | — | — |
| MCP Atlas | 58.2% ↗ | not reported | — | — |
| Multi-Challenge | 61% ↗ | not reported | — | — |
| Tau3-Bench (banking) | 19.6% ↗ | not reported | — | — |
| Terminal Bench Hard | 28.3% ↗ | not reported | — | — |
| Only Step 3.5 Flash reports · 14 | ||||
| AIME 2025 | not reported | 97.3% ↗ | — | — |
| LMArena Elo | not reported | 1403.7 ↗ | — | — |
| BrowseComp | not reported | 51.6% ↗ | — | — |
| 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% ↗ | — | — |
| 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 Solar Open 2 250B-A15B 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 | Solar Open 2 250B-A15B | Step 3.5 Flash | Edge |
|---|---|---|---|
| Context window | 1M tokens | 256K tokens | Solar Open 2 250B-A15B |
| Max output | — | — | — |
| Input price / 1M | — | — | — |
| Output price / 1M | — | — | — |
| Cached input / 1M | — | — | — |
| Input + output / 1M Lower is cheaper. List prices; batch, tool and regional fees excluded. | — | — | — |
| Modalities | text | text | Tie |
| Released | 2026-07-24 | 2026-02-12 | — |
| Cited benchmark scores | 16 | 18 | — |
Reliability
Provider status
Last 60 days · refreshed daily on this page · live on /statusMore matchups
Solar Open 2 250B-A15B 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 Solar Open 2 250B-A15B and Step 3.5 Flash on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.