Head to head · October 2026
GPT-5.5 vs Kimi K3 API pricing
Kimi K3 costs 4.2 times less per token at an 80/20 mix. Input costs 3.8x more on GPT-5.5. Output costs 4.6x more on GPT-5.5.
OpenAI
GPT-5.5
Reasoning-heavy tasks, research agents.
- Vendor
- OpenAI
- Type
- Frontier
- SayGM in / out
- $3.73 / $22.35
- OpenRouter in / out
- $5.28 / $31.65
- Blended, 80/20
- $7.454
- Per 100M tokens
- $745
- Output share of bill
- 60%
- SayGM vs OpenRouter
- 29% lower
Moonshot AI
Kimi K3
Open-weight coding and agent workloads.
- Vendor
- Moonshot AI
- Type
- Open weight, TEE variant available
- SayGM in / out
- $0.98 / $4.88
- OpenRouter in / out
- $0.42 / $9.50
- Blended, 80/20
- $1.760
- Per 100M tokens
- $176
- Output share of bill
- 55%
- SayGM vs OpenRouter
- 21% lower
§ 01
Monthly bill at three usage levels
Both models on SayGM. The bars show how the price ratio turns into dollars as volume grows.
- GPT-5.5 on SayGM
- Kimi K3 on SayGM
Show data as a table
| GPT-5.5 on SayGM | Kimi K3 on SayGM | |
|---|---|---|
| Side project (5M in · 1M out) | $41 | $9.78 |
| Production app (50M in · 15M out) | $522 | $122 |
| High volume (500M in · 100M out) | $4,100 | $978 |
§ 02
Verdict
A common pattern is to send routine requests to Kimi K3 and escalate to GPT-5.5 on failure or low confidence. On one key, that is a model name change per request rather than a second provider account.
§ 03
Per-token prices
OpenRouter figures include its 5.5% top-up fee.
| Model | SayGMin / out | OpenRouterin / out, fee incl. | SayGM vs OpenRouter80/20 blend |
|---|---|---|---|
| GPT-5.5OpenAI | $3.73 / $22.35 | $5.28 / $31.65 | 29% lower |
| Kimi K3Moonshot AI · TEE variant | $0.98 / $4.88 | $0.42 / $9.50Cheapest provider | 21% lower |
§ 04
GPT-5.5 vs Kimi K3 questions
Which is cheaper, GPT-5.5 or Kimi K3?
Kimi K3 is about 4.2 times cheaper than GPT-5.5 at an 80/20 input to output mix on SayGM, as of October 2026.
How much do GPT-5.5 and Kimi K3 cost on OpenRouter?
Including the 5.5 percent top-up fee, GPT-5.5 costs $5.28 input and $32 output per million tokens, and Kimi K3 costs $0.42 and $9.50.
Can I use GPT-5.5 and Kimi K3 with one API key?
Yes. SayGM serves both through their native APIs on a single key, so simple tasks can go to Kimi K3 and hard ones to GPT-5.5, or both can run in a cascade model.
§ 05