GLM 5.3 Prime vs GLM 5.3 FlashX: price, context window and capabilities
GLM 5.3 Prime (z-ai/glm-5.3-prime) is a language model from Z.ai and GLM 5.3 FlashX (z-ai/glm-5.3-flashx) a multimodal language model from Z.ai; both are on the OceanToken API. GLM 5.3 FlashX costs less per token than GLM 5.3 Prime: $0.37 against $2.80 per 1M input tokens (87% less) and $1.25 against $8.80 per 1M output tokens (86% less). GLM 5.3 FlashX has the larger context window: 1.05M tokens (1,048,576) against 1M (1,000,000) for GLM 5.3 Prime. Both support tool calling and reasoning; only GLM 5.3 FlashX also lists image input and video input.
Side by side
| Spec | GLM 5.3 Prime | GLM 5.3 FlashX |
|---|---|---|
| Model | GLM 5.3 Primez- | GLM 5.3 FlashXz- |
| Publisher | Z.ai | Z.ai |
| Kind | Text | Text, vision & video |
| Context window | 1M tokens1,000,000 | 1.05M tokens1,048,576 |
| Input price | $2.80 / 1M tokens | $0.37 / 1M tokens |
| Output price | $8.80 / 1M tokens | $1.25 / 1M tokens |
| Cached input price | $0.56 / 1M tokens | $0.09 / 1M tokens |
| Inputs | text | text, images and video |
| Outputs | text | text |
| Tool calling | Yes | Yes |
| Reasoning | Yes | Yes |
| Structured outputs | Not listed | Not listed |
About these prices
Which should you choose?
- Choose GLM 5.3 FlashX to spend less per token: 87% less for input and 86% less for output than GLM 5.3 Prime.
- Choose GLM 5.3 FlashX for the longest inputs: its context window holds 1.05M tokens against 1M for GLM 5.3 Prime.
- Choose GLM 5.3 FlashX if you need image input and video input: GLM 5.3 Prime does not list them.
- Not sure? Call both with the same OceanToken API key and compare them on your own prompts; each request is billed per use from one prepaid balance.
Get API Key GLM 5.3 Prime GLM 5.3 FlashX
Frequently asked questions
Which is cheaper, GLM 5.3 Prime or GLM 5.3 FlashX?
GLM 5.3 FlashX. GLM 5.3 FlashX costs less per token than GLM 5.3 Prime: $0.37 against $2.80 per 1M input tokens (87% less) and $1.25 against $8.80 per 1M output tokens (86% less). These are OceanToken starting prices per use; the OceanToken console always shows the current price.
Which has the larger context window, GLM 5.3 Prime or GLM 5.3 FlashX?
GLM 5.3 FlashX. GLM 5.3 FlashX has the larger context window: 1.05M tokens (1,048,576) against 1M (1,000,000) for GLM 5.3 Prime.
Can I call both GLM 5.3 Prime and GLM 5.3 FlashX with one API key?
Yes. Both are on the OceanToken API at https://api.oceantoken.ai/v1: one API key and one prepaid balance call either model. Send the model id z-ai/glm-5.3-prime or z-ai/glm-5.3-flashx.
Models and publishers
GLM 5.3 Prime · GLM 5.3 FlashX · All Z.ai models
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