Kimi K3 vs Step 3.7 Flash: cost comparison
Prices updated 2026-11-04 · computed from live provider data
Short answer: Step 3.7 Flash is cheaper on a
3:1 input/output blend — $0.438 per million tokens versus
$4.15, a 89% difference.
Kimi K3 offers the larger context window at 1,048,576 tokens, against 262,144 for Step 3.7 Flash.
Head to head
| Kimi K3 | Step 3.7 Flash | |
|---|---|---|
| Input, per 1M tokens | $0.200 | $0.200 |
| Output, per 1M tokens | $16.00 | $1.15 |
| Blended 3:1, per 1M | $4.15 | $0.438 |
| Context window | 1,048,576 | 262,144 |
| Vendor | moonshotai | stepfun |
Monthly cost at real volumes
| Workload (input / output) | Kimi K3 | Step 3.7 Flash |
|---|---|---|
| 1M in / 250K out | $4.20 | $0.487 |
| 10M in / 2.5M out | $42.00 | $4.88 |
| 100M in / 25M out | $420 | $48.75 |
Which should you pick?
Pick Kimi K3 when you need the longer context window (1,048,576 vs 262,144 tokens). Pick Step 3.7 Flash when price per token dominates your workload — high-volume classification, extraction, or batch summarisation.