Seed 2.0 Lite vs Step 3.5 Flash 2603
Seed 2.0 Lite comes out ahead, 73 to 62 on our weighted score, though Step 3.5 Flash 2603 is 25% cheaper per token.
- Our pick
ByteDance SeedSeed 2.0 Lite
73/100- ECI—
- Price$0.089 / $0.534
- Context256K
StepFunStep 3.5 Flash 2603
62/100- ECI—
- Price$0.10 / $0.30
- Context256K
Add a model
Make it a three-way comparison.
Seed 2.0 Lite is our pick
Seed 2.0 Lite is the better all-round choice, scoring 73/100 against Step 3.5 Flash 2603 (62). It leads on inputs & features. Step 3.5 Flash 2603 wins on price. 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 3.5 Flash 2603Step 3.5 Flash 2603 $0.15 · Seed 2.0 Lite $0.20 per 1M tokens (3:1 blend)
- Longest contextAbout the sameSeed 2.0 Lite 256,000 · Step 3.5 Flash 2603 256,000 tokens
- Widest inputsSeed 2.0 LiteSeed 2.0 Lite: Text, Images, Video · Step 3.5 Flash 2603: Text
- Self-hostingStep 3.5 Flash 2603Publishes downloadable weights
| Measure | Weight | Seed 2.0 Lite | Step 3.5 Flash 2603 |
|---|---|---|---|
| Price | 50% | 83 | 89 |
| Inputs & features | 30% | 80 | 35 |
| Context window | 20% | 36 | 36 |
| Overall | 100% | 73/100 | 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 | Seed 2.0 LiteByteDance Seed | Step 3.5 Flash 2603StepFun |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | — | — |
| ECI rank | — | — |
| Price per million tokens | ||
| Input | $0.089 (best) | $0.10 |
| Output | $0.534 | $0.30 (best) |
| Cached input | $0.018 (best) | $0.02 |
| Blended (3:1) | $0.20 | $0.15 (best) |
| Long-context rate | Over 32K: $0.134 / $0.802 | Same rate |
| Price source | Official Volcengine Ark API | Official StepFun (Global) API |
| Limits | ||
| Context window | 256,000 tokens | 256,000 tokens |
| Max output | 32,000 tokens | 256,000 tokens (best) |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | Yes | No |
| PDFs | No | No |
| Audio | No | No |
| Video | Yes | No |
| Reasoning | Yesminimal · low · medium · high · xhigh · max | Yeslow · high |
| Tool calling | Yes | Yes |
| Structured output | Yes | No |
| Availability | ||
| Weights | Proprietary | Open |
| API model ID | doubao-seed-2-0-lite-260428 | step-3.5-flash-2603 |
| API providers | 6 (best) | 3 |
| Released | Feb 14, 2026 | Apr 2, 2026 |
| Knowledge cutoff | — | Jan 2025 |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Seed 2.0 Lite$1.96
- Step 3.5 Flash 2603$1.60
Which should you choose?
Which is better: Seed 2.0 Lite or Step 3.5 Flash 2603?
Seed 2.0 Lite is the better all-round choice, scoring 73/100 against Step 3.5 Flash 2603 (62). It leads on inputs & features. Step 3.5 Flash 2603 wins on price. 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, Seed 2.0 Lite or Step 3.5 Flash 2603?
Step 3.5 Flash 2603 is cheaper at $0.10 input / $0.30 output per million tokens (official StepFun (Global) API price). Seed 2.0 Lite costs $0.089 input / $0.534 output per million tokens (official Volcengine Ark API price). At a typical mix of three input tokens to one output token, that is $0.15 per million tokens for Step 3.5 Flash 2603 versus $0.20 for Seed 2.0 Lite (1.3× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers both models yet. Seed 2.0 Lite has not been scored yet and Step 3.5 Flash 2603 has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for Seed 2.0 Lite and Step 3.5 Flash 2603 yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Both support tool calling for agent workflows.
Which has the bigger context window?
Seed 2.0 Lite and Step 3.5 Flash 2603 share the same 256,000-token context window. Maximum output per response: Seed 2.0 Lite up to 32,000, Step 3.5 Flash 2603 up to 256,000 tokens.
Which can read images, PDFs, audio or video?
Seed 2.0 Lite accepts text, images and video; Step 3.5 Flash 2603 accepts text. Seed 2.0 Lite handles the widest range of inputs.
Are any of these open source?
Step 3.5 Flash 2603 publishes its weights and can be self-hosted; Seed 2.0 Lite is proprietary.
Which is newer?
Step 3.5 Flash 2603 is the newest, released Apr 2, 2026. Seed 2.0 Lite came out Feb 14, 2026. Knowledge cutoff: Step 3.5 Flash 2603 Jan 2025.
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.
