Step 3.5 Flash vs Pareto 26.10 Preview
Step 3.5 Flash costs 10.7x less per output token than Pareto 26.10 Preview ($0.30 vs $3.20 per million). Updated November 14, 2026; no benchmark has tested both models yet.
- Coding
- No data
- Overall
- No data
- Output $/M
- $0.30
- Coding
- No data
- Overall
- No data
- Output $/M
- $3.20
Step 3.5 Flash or Pareto 26.10 Preview: which to pick
Neither model has a coding score yet, so the two cannot be ranked on coding.
Pick Step 3.5 Flash for output tokens 10.7x cheaper ($0.30 vs $3.20 per million).
No benchmark has tested both yet. Step 3.5 Flash has results on Terminal-Bench Hard (Artificial Analysis run), LMArena Text: coding and LMArena Text: software and IT; Pareto 26.10 Preview on GameBench 2. Compare them on price and context instead.
Which one for your work
Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.
Coding
Vibe Coding Index, six public coding benchmarks
No call
Neither has a coding score yet.
One side not measured
Long documents
Listed context window
Pareto 26.10 Preview
Pareto 26.10 Preview takes 1.05M tokens against 262K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Step 3.5 Flash
Step 3.5 Flash $0.0003, Pareto 26.10 Preview $0.0024 per turn.
List prices
At a glance
- Coding index
- Step 3.5 Flash not benchmarked, Pareto 26.10 Preview not benchmarked.
- Widest category
- None yet: no category has been tested on both models.
- Widest single gap
- None yet: no benchmark has tested both models.
- Output price
- Step 3.5 Flash $0.30 against Pareto 26.10 Preview $3.20 per million output tokens, 10.7x apart.
- Context window
- Step 3.5 Flash takes 262K tokens, Pareto 26.10 Preview 1.05M.
Benchmark by benchmark
Every board either model has a result on, a category to a fold; bars are each result on a 0 to 100 scale. Only one model is measured on each, so no row names a leader.
CodingDirectional onlySix of these boards feed the Vibe Coding Index4 boards measured
| Benchmark | Step 3.5 Flash | Pareto 26.10 Preview | Leader |
|---|---|---|---|
| Terminal-Bench Hard (Artificial Analysis run) | 32.6% | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: coding | 1435 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: software and IT | 1434 | Not measured | Only Step 3.5 Flash measured |
| GameBench 2 | Not measured | 88.3 | Only Pareto 26.10 Preview measured |
| Neither model has a result on the other 48 boards here | |||
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index1 board measured
| Benchmark | Step 3.5 Flash | Pareto 26.10 Preview | Leader |
|---|---|---|---|
| τ²-Bench Telecom | 94.4% | Not measured | Only Step 3.5 Flash measured |
| Neither model has a result on the other 43 boards here | |||
ReasoningDirectional onlyPublic boards, shown as published, kept out of the index5 boards measured
| Benchmark | Step 3.5 Flash | Pareto 26.10 Preview | Leader |
|---|---|---|---|
| GPQA Diamond (Artificial Analysis run) | 83.1% | Not measured | Only Step 3.5 Flash measured |
| Humanity's Last Exam (Artificial Analysis run) | 24.5% | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: hard prompts | 1410 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: expert | 1421 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: hard prompts in English | 1420 | Not measured | Only Step 3.5 Flash measured |
| Neither model has a result on the other 21 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index3 boards measured
| Benchmark | Step 3.5 Flash | Pareto 26.10 Preview | Leader |
|---|---|---|---|
| LMArena Text: math | 1406 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: mathematical work | 1419 | Not measured | Only Step 3.5 Flash measured |
| MathArena | 18.7% | Not measured | Only Step 3.5 Flash measured |
| Neither model has a result on the other 11 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index4 boards measured
| Benchmark | Step 3.5 Flash | Pareto 26.10 Preview | Leader |
|---|---|---|---|
| LMArena Text: science | 1414 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: medicine and healthcare | 1408 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: legal and government | 1407 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: business and finance | 1394 | Not measured | Only Step 3.5 Flash measured |
| Neither model has a result on the other 17 boards here | |||
GeneralDirectional onlyPublic boards, shown as published, kept out of the index19 boards measured
| Benchmark | Step 3.5 Flash | Pareto 26.10 Preview | Leader |
|---|---|---|---|
| IFBench | 66.5% | Not measured | Only Step 3.5 Flash measured |
| Long context reasoning (AA-LCR) | 63.0% | Not measured | Only Step 3.5 Flash measured |
| LMArena Text | 1402 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: instruction following | 1385 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: creative writing | 1357 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: English | 1417 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: non-English | 1385 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: Chinese | 1446 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: German | 1403 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: Japanese | 1353 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: Korean | 1350 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: French | 1421 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: Spanish | 1418 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: Russian | 1385 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: Polish | 1388 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: multi-turn | 1404 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: longer queries | 1402 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: writing and language | 1371 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: entertainment and media | 1359 | Not measured | Only Step 3.5 Flash measured |
| Neither model has a result on the other 30 boards here | |||
What each workload costs
Three fixed token mixes at each model's listed price, so per-token rates become a bill.
Chat turn
1K input + 500 output tokens
Step 3.5 Flash costs less
Repository review
50K input + 3K output tokens
Step 3.5 Flash costs less
Agent loop
200K input + 10K output tokens
Step 3.5 Flash costs less
Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.
Specification differences
The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.
| Specification | StepFun Step 3.5 Flash | Pareto 26.10 Preview |
|---|---|---|
| Maker | StepFun | Unbiased |
| Weights | Open weights | No public weights listed |
| Released | January 29, 2026 | October 1, 2026 |
| Context window | 262K | 1.05M |
| Input $/Mtok | $0.10 | $0.80 |
| Output $/Mtok | $0.30 | $3.20 |
| Coding index | Not benchmarked | Not benchmarked |
| Independent measurements behind it | 0 | 0 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Step 3.5 Flash better than Pareto 26.10 Preview for coding?
Neither model has a coding score yet, so the two cannot be ranked on coding. Pick Step 3.5 Flash for output tokens 10.7x cheaper ($0.30 vs $3.20 per million).
Which is cheaper, Step 3.5 Flash or Pareto 26.10 Preview?
Step 3.5 Flash costs $0.10 per million input tokens and $0.30 per million output tokens; Pareto 26.10 Preview costs $0.80 and $3.20. Cost per solved task is known for neither of them.
Which has the bigger context window, Step 3.5 Flash or Pareto 26.10 Preview?
Pareto 26.10 Preview, with 1.05M tokens against 262K.
Has any benchmark tested both Step 3.5 Flash and Pareto 26.10 Preview?
No benchmark has tested both yet. Step 3.5 Flash has results on Terminal-Bench Hard (Artificial Analysis run), LMArena Text: coding and LMArena Text: software and IT; Pareto 26.10 Preview on GameBench 2. Compare them on price and context instead. Data as of November 14, 2026.