GLM 5.3 Prime vs GPT-6 Astra: price, context window and capabilities
GLM 5.3 Prime (z-ai/glm-5.3-prime) is a language model from Z.ai and GPT-6 Astra (openai/gpt-6-astra) a multimodal language model from OpenAI; both are on the OceanToken API. GLM 5.3 Prime costs less per token than GPT-6 Astra: $2.80 against $9.00 per 1M input tokens (69% less) and $8.80 against $45.00 per 1M output tokens (80% less). GPT-6 Astra is 10% off its official price on OceanToken, for every account. GPT-6 Astra has the larger context window: 1.05M tokens (1,050,000) against 1M (1,000,000) for GLM 5.3 Prime. Both support tool calling and reasoning; only GPT-6 Astra also lists structured outputs, image input and file input.
Side by side
| Spec | GLM 5.3 Prime | GPT-6 Astra −10% |
|---|---|---|
| Model | GLM 5.3 Primez- | GPT-6 Astraopenai/ |
| Publisher | Z.ai | OpenAI |
| Kind | Text | Text & vision |
| Context window | 1M tokens1,000,000 | 1.05M tokens1,050,000 |
| Input price | $2.80 / 1M tokens | $9.00 / 1M tokens |
| Output price | $8.80 / 1M tokens | $45.00 / 1M tokens |
| Cached input price | $0.56 / 1M tokens | $1.00 / 1M tokens |
| Cache write price | – | $12.50 / 1M tokens |
| Web search price | – | $0.01 / search |
| Discount (vs official, top tier) | — | −10% |
| Inputs | text | text, images and files |
| Outputs | text | text |
| Tool calling | Yes | Yes |
| Reasoning | Yes | Yes |
| Structured outputs | Not listed | Yes |
About these prices
Which should you choose?
- Choose GLM 5.3 Prime to spend less per token: 69% less for input and 80% less for output than GPT-6 Astra.
- Choose GPT-6 Astra for the longest inputs: its context window holds 1.05M tokens against 1M for GLM 5.3 Prime.
- Choose GPT-6 Astra if you need structured outputs, image input and file 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 GPT-6 Astra
Frequently asked questions
Which is cheaper, GLM 5.3 Prime or GPT-6 Astra?
GLM 5.3 Prime. GLM 5.3 Prime costs less per token than GPT-6 Astra: $2.80 against $9.00 per 1M input tokens (69% less) and $8.80 against $45.00 per 1M output tokens (80% less). GPT-6 Astra 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 GPT-6 Astra?
GPT-6 Astra. GPT-6 Astra has the larger context window: 1.05M tokens (1,050,000) against 1M (1,000,000) for GLM 5.3 Prime.
Can I call both GLM 5.3 Prime and GPT-6 Astra 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 openai/gpt-6-astra.
Models and publishers
GLM 5.3 Prime · GPT-6 Astra · All Z.ai models · All OpenAI models
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