Beam 1.0 501B A23B vs Step 3.5 Flash
Step 3.5 Flash costs 3.7x less per output token than Beam 1.0 501B A23B ($0.30 vs $1.10 per million). Updated October 21, 2026; 23 benchmarks have a result for both.
Beam 1.0 501B A23B or Step 3.5 Flash: which to pick
Neither model has a coding score yet, so the two cannot be ranked on coding.
Pick Beam 1.0 501B A23B for a larger context window (1.05M against 262K tokens) and work measured by LMArena Text: medicine and healthcare or LMArena Text: Chinese, where it leads.
- Shared results
- 23
- Beam 1.0 501B A23B only
- 5
- Step 3.5 Flash only
- 12
- Like-for-like categories
- 5 of 9
Only benchmarks that tested both models count toward a pick; a result only one model has is shown but not compared.
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
Intelligence
AA Intelligence Index
No call
Only Step 3.5 Flash has a AA Intelligence Index result, 17.0.
Directional only
Web design
Design Arena: websites
No call
Only Beam 1.0 501B A23B has a Design Arena: websites result, 1253.
Directional only
Long documents
Listed context window
Beam 1.0 501B A23B
Beam 1.0 501B A23B takes 1.05M tokens against 262K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Step 3.5 Flash
Beam 1.0 501B A23B $0.0009, Step 3.5 Flash $0.0003 per turn.
List prices
At a glance
- Coding index
- Beam 1.0 501B A23B not benchmarked, Step 3.5 Flash not benchmarked.
- Widest category
- Math, 8.7 points apart on average over 2 shared benchmarks.
- Widest single gap
- LMArena Text: mathematical work: Beam 1.0 501B A23B 1475 against Step 3.5 Flash 1421, 9.0 points apart on a 0 to 100 scale.
- Output price
- Beam 1.0 501B A23B $1.10 against Step 3.5 Flash $0.30 per million output tokens, 3.7x apart.
- Context window
- Beam 1.0 501B A23B takes 1.05M tokens, Step 3.5 Flash 262K.
Benchmark by benchmark
First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.
| Category | Beam 1.0 501B A23B | Bars | Step 3.5 Flash | Ties |
|---|---|---|---|---|
| Coding | 2 | 0 | ||
| Reasoning | 3 | 0 | ||
| Math | 2 | 0 | ||
| Knowledge | 3 | 1 | ||
| General | 11 | 1 | ||
| All shared boards | 21 | 2 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index20
| Benchmark | Beam 1.0 501B A23B | Step 3.5 Flash | Leader |
|---|---|---|---|
| LMArena WebDev | 1437 | Not measured | Only Beam 1.0 501B A23B measured |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 32.6% | Only Step 3.5 Flash measured |
| LMArena Text: coding | 1473 | 1436 | Beam 1.0 501B A23B |
| LMArena Text: software and IT | 1461 | 1434 | Beam 1.0 501B A23B |
| LMArena WebDev: React | 1443 | Not measured | Only Beam 1.0 501B A23B measured |
| LMArena WebDev: HTML | 1436 | Not measured | Only Beam 1.0 501B A23B measured |
| Neither model has a result on the other 33 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | Beam 1.0 501B A23B | Step 3.5 Flash | Leader |
|---|---|---|---|
| AA Intelligence Index | Not measured | 17.0 | Only Step 3.5 Flash measured |
| Neither model has a result on the other 1 board here | |||
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | Beam 1.0 501B A23B | Step 3.5 Flash | Leader |
|---|---|---|---|
| τ²-Bench Telecom | Not measured | 94.4% | Only Step 3.5 Flash measured |
| Neither model has a result on the other 40 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index30
| Benchmark | Beam 1.0 501B A23B | Step 3.5 Flash | Leader |
|---|---|---|---|
| GPQA Diamond (Artificial Analysis run) | Not measured | 83.1% | Only Step 3.5 Flash measured |
| Humanity's Last Exam (Artificial Analysis run) | Not measured | 24.5% | Only Step 3.5 Flash measured |
| LMArena Text: hard prompts | 1442 | 1411 | Beam 1.0 501B A23B |
| LMArena Text: expert | 1447 | 1421 | Beam 1.0 501B A23B |
| LMArena Text: hard prompts in English | 1451 | 1421 | Beam 1.0 501B A23B |
| Neither model has a result on the other 17 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Beam 1.0 501B A23B | Step 3.5 Flash | Leader |
|---|---|---|---|
| LMArena Text: math | 1459 | 1408 | Beam 1.0 501B A23B |
| LMArena Text: mathematical work | 1475 | 1421 | Beam 1.0 501B A23B |
| Neither model has a result on the other 11 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index31
| Benchmark | Beam 1.0 501B A23B | Step 3.5 Flash | Leader |
|---|---|---|---|
| LMArena Text: science | 1430 | 1415 | Beam 1.0 501B A23B |
| LMArena Text: medicine and healthcare | 1376 | 1408 | Step 3.5 Flash |
| LMArena Text: legal and government | 1433 | 1408 | Beam 1.0 501B A23B |
| LMArena Text: business and finance | 1430 | 1394 | Beam 1.0 501B A23B |
| Neither model has a result on the other 14 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | Beam 1.0 501B A23B | Step 3.5 Flash | Leader |
|---|---|---|---|
| Design Arena: websites | 1253 | Not measured | Only Beam 1.0 501B A23B measured |
| Design Arena: game dev | 1233 | Not measured | Only Beam 1.0 501B A23B measured |
| Neither model has a result on the other 7 boards here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index111
| Benchmark | Beam 1.0 501B A23B | Step 3.5 Flash | Leader |
|---|---|---|---|
| IFBench | Not measured | 66.5% | Only Step 3.5 Flash measured |
| Long context reasoning (AA-LCR) | Not measured | 63.0% | Only Step 3.5 Flash measured |
| LMArena Text | 1425 | 1403 | Beam 1.0 501B A23B |
| LMArena Text: instruction following | 1430 | 1385 | Beam 1.0 501B A23B |
| LMArena Text: creative writing | 1390 | 1357 | Beam 1.0 501B A23B |
| LMArena Text: English | 1436 | 1417 | Beam 1.0 501B A23B |
| LMArena Text: non-English | 1413 | 1385 | Beam 1.0 501B A23B |
| LMArena Text: Chinese | 1424 | 1446 | Step 3.5 Flash |
| LMArena Text: German | Not measured | 1405 | Only Step 3.5 Flash measured |
| LMArena Text: Japanese | Not measured | 1353 | Only Step 3.5 Flash measured |
| LMArena Text: Korean | Not measured | 1351 | Only Step 3.5 Flash measured |
| LMArena Text: French | 1461 | 1421 | Beam 1.0 501B A23B |
| LMArena Text: Spanish | Not measured | 1419 | Only Step 3.5 Flash measured |
| LMArena Text: Russian | 1412 | 1385 | Beam 1.0 501B A23B |
| LMArena Text: Polish | Not measured | 1389 | Only Step 3.5 Flash measured |
| LMArena Text: multi-turn | 1414 | 1404 | Beam 1.0 501B A23B |
| LMArena Text: longer queries | 1429 | 1402 | Beam 1.0 501B A23B |
| LMArena Text: writing and language | 1400 | 1372 | Beam 1.0 501B A23B |
| LMArena Text: entertainment and media | 1399 | 1360 | Beam 1.0 501B A23B |
| Neither model has a result on the other 27 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Beam 1.0 501B A23B | Step 3.5 Flash | Leader |
|---|---|---|---|
| Neither model has a result on 5 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 | Reflection Beam 1.0 501B A23B | StepFun Step 3.5 Flash |
|---|---|---|
| Maker | Reflection | StepFun |
| Weights | Open weights | Open weights |
| Released | October 16, 2026 | January 29, 2026 |
| Context window | 1.05M | 262K |
| Input $/Mtok | $0.35 | $0.10 |
| Output $/Mtok | $1.10 | $0.30 |
| Coding index | Not benchmarked | Not benchmarked |
| Independent measurements behind it | 1 | 0 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Beam 1.0 501B A23B better than Step 3.5 Flash for coding?
Neither model has a coding score yet, so the two cannot be ranked on coding. Pick Beam 1.0 501B A23B for a larger context window (1.05M against 262K tokens) and work measured by LMArena Text: medicine and healthcare or LMArena Text: Chinese, where it leads.
Which is cheaper, Beam 1.0 501B A23B or Step 3.5 Flash?
Beam 1.0 501B A23B costs $0.35 per million input tokens and $1.10 per million output tokens; Step 3.5 Flash costs $0.10 and $0.30. Cost per solved task is known for neither of them.
Which has the bigger context window, Beam 1.0 501B A23B or Step 3.5 Flash?
Beam 1.0 501B A23B, with 1.05M tokens against 262K.
How many benchmarks is the Beam 1.0 501B A23B vs Step 3.5 Flash comparison based on?
23 benchmarks have a result for both models as of October 21, 2026. Beam 1.0 501B A23B's coding index rests on 1 independent benchmark and Step 3.5 Flash's on 0. Where only one model has a result, the page says so instead of naming a winner.