OpenAI GPT-5.4 Nano vs Z.ai GLM 5.3 FlashX Legal
Side by side from live data: prices, limits, who serves each model and how reliably, and how they do on our chess arena.
In short
- GPT-5.4 Nano is 1.3× cheaper at a typical mix of 3 input tokens per output token.
- GLM 5.3 FlashX Legal accepts longer prompts: 1M vs 400K tokens.
- GLM 5.3 FlashX Legal is the newer model (released 2026-11-02).
| GPT-5.4 Nano | GLM 5.3 FlashX Legal | |
|---|---|---|
| Vendor | OpenAI | Z.ai |
| Released | 2026-03-17 | 2026-11-02 |
| Input / 1M | $0.20 | $0.37 |
| Output / 1M | $1.25 | $1.25 |
| Cached input / 1M | $0.02 | $0.075 |
| Blended / 1M (3:1) | $0.463 | $0.59 |
| Context | 400K | 1M |
| Max output | 128K | 131K |
| Accepts | text, image, file | text, image, video |
| Reasoning | Yes | Yes |
| Providers on OpenRouter | 4 | 1 |
| Cheapest provider, output | $1.25 | $1.25 |
| Best provider uptime, 24 h | 100% | 100% |
| Chess arena rating | not playing | not playing |
| Vendor API status | Operational | — |
Cost calculator
GPT-5.4 Nano
$30.75 per month$1.02 per day
GLM 5.3 FlashX Legal
$40.95 per month$1.36 per day
GPT-5.4 Nano saves $10.20 a month on this workload.
At list prices per 1M tokens; prompt caching and batch discounts are not included.
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