Seed 2.0 Mini vs Step 3.5 Flash: cost comparison
Prices updated 2026-10-27 · computed from live provider data
Short answer: Step 3.5 Flash is cheaper on a
3:1 input/output blend — $0.150 per million tokens versus
$0.175, a 14% difference.
Both offer the same 262,144-token context window, so cost is the deciding factor.
Head to head
| Seed 2.0 Mini | Step 3.5 Flash | |
|---|---|---|
| Input, per 1M tokens | $0.100 | $0.100 |
| Output, per 1M tokens | $0.400 | $0.300 |
| Blended 3:1, per 1M | $0.175 | $0.150 |
| Context window | 262,144 | 262,144 |
| Vendor | bytedance-seed | stepfun |
Monthly cost at real volumes
| Workload (input / output) | Seed 2.0 Mini | Step 3.5 Flash |
|---|---|---|
| 1M in / 250K out | $0.200 | $0.175 |
| 10M in / 2.5M out | $2.00 | $1.75 |
| 100M in / 25M out | $20.00 | $17.50 |
Which should you pick?
Because the context windows are identical, the cheaper option is the better default. Choose Step 3.5 Flash unless you are already standardised on bytedance-seed tooling and want to avoid a second integration.