GLM 5.3 Prime vs Gemini 3.8 Flash: price, context window and capabilities
GLM 5.3 Prime (z-ai/glm-5.3-prime) is a language model from Z.ai and Gemini 3.8 Flash (google/gemini-3.8-flash) a multimodal language model from Google; both are on the OceanToken API. Gemini 3.8 Flash costs less per token than GLM 5.3 Prime: $0.675 against $2.80 per 1M input tokens (76% less) and $3.375 against $8.80 per 1M output tokens (62% less). Gemini 3.8 Flash is 10% off its official price on OceanToken, for every account. Gemini 3.8 Flash 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 Gemini 3.8 Flash also lists structured outputs, image input, file input, audio input and video input.
Side by side
| Spec | GLM 5.3 Prime | Gemini 3.8 Flash −10% |
|---|---|---|
| Model | GLM 5.3 Primez- | Gemini 3.8 Flashgoogle/ |
| Publisher | Z.ai | |
| Kind | Text | Text, vision, audio & video |
| Context window | 1M tokens1,000,000 | 1.05M tokens1,048,576 |
| Input price | $2.80 / 1M tokens | $0.675 / 1M tokens |
| Output price | $8.80 / 1M tokens | $3.375 / 1M tokens |
| Cached input price | $0.56 / 1M tokens | $0.075 / 1M tokens |
| Cache write price | – | $0.792 / 1M tokens |
| Web search price | – | $0.014 / search |
| Discount (vs official, top tier) | — | −10% |
| Inputs | text | text, images, files, audio and video |
| Outputs | text | text |
| Tool calling | Yes | Yes |
| Reasoning | Yes | Yes |
| Structured outputs | Not listed | Yes |
About these prices
Which should you choose?
- Choose Gemini 3.8 Flash to spend less per token: 76% less for input and 62% less for output than GLM 5.3 Prime.
- Choose Gemini 3.8 Flash for the longest inputs: its context window holds 1.05M tokens against 1M for GLM 5.3 Prime.
- Choose Gemini 3.8 Flash if you need structured outputs, image input, file input, audio 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 Gemini 3.8 Flash
Frequently asked questions
Which is cheaper, GLM 5.3 Prime or Gemini 3.8 Flash?
Gemini 3.8 Flash. Gemini 3.8 Flash costs less per token than GLM 5.3 Prime: $0.675 against $2.80 per 1M input tokens (76% less) and $3.375 against $8.80 per 1M output tokens (62% less). Gemini 3.8 Flash is 10% off its official price on OceanToken, for every account. The OceanToken console always shows the current price.
Which has the larger context window, GLM 5.3 Prime or Gemini 3.8 Flash?
Gemini 3.8 Flash. Gemini 3.8 Flash 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 Gemini 3.8 Flash 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 google/gemini-3.8-flash.
Models and publishers
GLM 5.3 Prime · Gemini 3.8 Flash · All Z.ai models · All Google models
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