GLM 5.3 Prime vs Claude Sonnet 5.5: price, context window and capabilities
GLM 5.3 Prime (z-ai/glm-5.3-prime) is a language model from Z.ai and Claude Sonnet 5.5 (anthropic/claude-sonnet-5.5) a multimodal language model from Anthropic; both are on the OceanToken API. GLM 5.3 Prime costs less for output: $8.80 against $9.00 per 1M output tokens (2% less); Claude Sonnet 5.5 costs less for input: $1.80 against $2.80 per 1M input tokens (36% less). Claude Sonnet 5.5 is 10% off its official price on OceanToken, for every account. Both have a 1M-token context window (1,000,000 tokens). Both support tool calling and reasoning; only Claude Sonnet 5.5 also lists structured outputs, image input and file input.
Side by side
| Spec | GLM 5.3 Prime | Claude Sonnet 5.5 −10% |
|---|---|---|
| Model | GLM 5.3 Primez- | Claude Sonnet 5.5anthropic/ |
| Publisher | Z.ai | Anthropic |
| Kind | Text | Text & vision |
| Context window | 1M tokens1,000,000 | 1M tokens1,000,000 |
| Input price | $2.80 / 1M tokens | $1.80 / 1M tokens |
| Output price | $8.80 / 1M tokens | $9.00 / 1M tokens |
| Cached input price | $0.56 / 1M tokens | $0.10 / 1M tokens |
| Cache write price | – | $2.50 / 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?
- Price depends on the mix: GLM 5.3 Prime costs less for output and Claude Sonnet 5.5 for input, so estimate both on your own volume of input tokens and output tokens.
- Context size does not separate them: both hold about 1M tokens.
- Choose Claude Sonnet 5.5 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 Claude Sonnet 5.5
Frequently asked questions
Which is cheaper, GLM 5.3 Prime or Claude Sonnet 5.5?
It depends on the mix of tokens. GLM 5.3 Prime costs less for output: $8.80 against $9.00 per 1M output tokens (2% less); Claude Sonnet 5.5 costs less for input: $1.80 against $2.80 per 1M input tokens (36% less). Claude Sonnet 5.5 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 Claude Sonnet 5.5?
Neither. Both have a 1M-token context window (1,000,000 tokens).
Can I call both GLM 5.3 Prime and Claude Sonnet 5.5 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 anthropic/claude-sonnet-5.5.
Models and publishers
GLM 5.3 Prime · Claude Sonnet 5.5 · All Z.ai models · All Anthropic models
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