Nex-N2-Pro vs Seed 2.1 Turbo vs Step 3.7 Flash
Step 3.7 Flash comes out ahead, 62 to 57 and 53 on our weighted score, and it is the cheaper option too.
Nex AGI
Nex-N2-Pro
53/100- ECI—
- Price$0.50 / $2.50
- Context262K
ByteDance SeedSeed 2.1 Turbo
57/100- ECI—
- Price$0.445 / $2.23
- Context256K
- Our pick
StepFunStep 3.7 Flash
62/100- ECI—
- Price$0.185 / $1.11
- Context256K
Step 3.7 Flash is our pick
Step 3.7 Flash is the better all-round choice, scoring 62/100 against Seed 2.1 Turbo (57) and Nex-N2-Pro (53). It leads on price. Seed 2.1 Turbo wins on inputs & features. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
- CapabilityNot enough dataNo independent benchmark covers every model here yet
- Lowest priceStep 3.7 FlashStep 3.7 Flash $0.416 · Seed 2.1 Turbo $0.891 · Nex-N2-Pro $1.00 per 1M tokens (3:1 blend)
- Longest contextNex-N2-ProNex-N2-Pro 262,144 · Seed 2.1 Turbo 256,000 · Step 3.7 Flash 256,000 tokens
- Widest inputsSeed 2.1 Turbo and Step 3.7 FlashNex-N2-Pro: Text, Images · Seed 2.1 Turbo: Text, Images, Video · Step 3.7 Flash: Text, Images, Video
- Self-hostingNex-N2-Pro and Step 3.7 FlashPublishes downloadable weights
| Measure | Weight | Nex-N2-Pro | Seed 2.1 Turbo | Step 3.7 Flash |
|---|---|---|---|---|
| Price | 50% | 50 | 52 | 68 |
| Inputs & features | 30% | 70 | 80 | 70 |
| Context window | 20% | 37 | 36 | 36 |
| Overall | 100% | 53/100 | 57/100 | 62/100 |
Left out because at least one model lacks the data: capability. The remaining weights were rescaled.
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Nex-N2-ProNex AGI | Seed 2.1 TurboByteDance Seed | Step 3.7 FlashStepFun |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | — | — | — |
| ECI rank | — | — | — |
| Price per million tokens | |||
| Input | $0.50 | $0.445 | $0.185 (best) |
| Output | $2.50 | $2.23 | $1.11 (best) |
| Cached input | — | $0.089 | $0.037 (best) |
| Blended (3:1) | $1.00 | $0.891 | $0.416 (best) |
| Long-context rate | Same rate | Same rate | Same rate |
| Price source | Median of 1 providers | Official Volcengine Ark API | Official StepFun (Global) API |
| Limits | |||
| Context window | 262,144 tokens (best) | 256,000 tokens | 256,000 tokens |
| Max output | 262,144 tokens (best) | 256,000 tokens | 256,000 tokens |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | Yes |
| PDFs | No | No | No |
| Audio | No | No | No |
| Video | No | Yes | Yes |
| Reasoning | Yes | Yesminimal · low · medium · high · xhigh · max | Yeslow · medium · high |
| Tool calling | Yes | Yes | Yes |
| Structured output | Yes | Yes | No |
| Availability | |||
| Weights | Open | Proprietary | Open |
| API model ID | — | doubao-seed-2-1-turbo-260628 | step-3.7-flash |
| API providers | 1 | 4 | 18 (best) |
| Released | Jun 2, 2026 | Jun 23, 2026 | May 29, 2026 |
| Knowledge cutoff | — | — | Mar 1, 2026 |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Nex-N2-Pro$10.00
- Seed 2.1 Turbo$8.91
- Step 3.7 Flash$4.07
Which should you choose?
Which is better: Nex-N2-Pro, Seed 2.1 Turbo or Step 3.7 Flash?
Step 3.7 Flash is the better all-round choice, scoring 62/100 against Seed 2.1 Turbo (57) and Nex-N2-Pro (53). It leads on price. Seed 2.1 Turbo wins on inputs & features. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
Which is cheaper, Nex-N2-Pro, Seed 2.1 Turbo or Step 3.7 Flash?
Step 3.7 Flash is cheaper at $0.185 input / $1.11 output per million tokens (official StepFun (Global) API price). Seed 2.1 Turbo costs $0.445 input / $2.23 output per million tokens (official Volcengine Ark API price); Nex-N2-Pro costs $0.50 input / $2.50 output per million tokens (median across 1 API provider). At a typical mix of three input tokens to one output token, that is $0.416 per million tokens for Step 3.7 Flash versus $0.891 for Seed 2.1 Turbo (2.1× as much) and $1.00 for Nex-N2-Pro (2.4× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers all three models yet. Nex-N2-Pro has not been scored yet, Seed 2.1 Turbo has not been scored yet and Step 3.7 Flash has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for Nex-N2-Pro, Seed 2.1 Turbo and Step 3.7 Flash yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. All three support tool calling for agent workflows.
Which has the bigger context window?
Nex-N2-Pro has the largest context window at 262,144 tokens, against 256,000 for Seed 2.1 Turbo and 256,000 for Step 3.7 Flash. Maximum output per response: Nex-N2-Pro up to 262,144, Seed 2.1 Turbo up to 256,000, Step 3.7 Flash up to 256,000 tokens.
Which can read images, PDFs, audio or video?
Nex-N2-Pro accepts text and images; Seed 2.1 Turbo accepts text, images and video; Step 3.7 Flash accepts text, images and video. Seed 2.1 Turbo handles the widest range of inputs.
Are any of these open source?
Nex-N2-Pro and Step 3.7 Flash publishes its weights and can be self-hosted; Seed 2.1 Turbo is proprietary.
Which is newer?
Seed 2.1 Turbo is the newest, released Jun 23, 2026. Nex-N2-Pro came out Jun 2, 2026; Step 3.7 Flash came out May 29, 2026. Knowledge cutoff: Step 3.7 Flash Mar 1, 2026.
How do you decide the winner?
Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Oct 4, 2026.
