GLM 5.3 Prime vs Claude Opus 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 Opus 5.5 (anthropic/claude-opus-5.5) a multimodal language model from Anthropic; both are on the OceanToken API. GLM 5.3 Prime costs less per token than Claude Opus 5.5: $2.80 against $3.60 per 1M input tokens (22% less) and $8.80 against $18.00 per 1M output tokens (51% less). Claude Opus 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 Opus 5.5 also lists structured outputs, image input and file input.
Side by side
| Spec | GLM 5.3 Prime | Claude Opus 5.5 −10% |
|---|---|---|
| Model | GLM 5.3 Primez- | Claude Opus 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 | $3.60 / 1M tokens |
| Output price | $8.80 / 1M tokens | $18.00 / 1M tokens |
| Cached input price | $0.56 / 1M tokens | $0.20 / 1M tokens |
| Cache write price | – | $5.00 / 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: 22% less for input and 51% less for output than Claude Opus 5.5.
- Context size does not separate them: both hold about 1M tokens.
- Choose Claude Opus 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 Opus 5.5
Frequently asked questions
Which is cheaper, GLM 5.3 Prime or Claude Opus 5.5?
GLM 5.3 Prime. GLM 5.3 Prime costs less per token than Claude Opus 5.5: $2.80 against $3.60 per 1M input tokens (22% less) and $8.80 against $18.00 per 1M output tokens (51% less). Claude Opus 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 Opus 5.5?
Neither. Both have a 1M-token context window (1,000,000 tokens).
Can I call both GLM 5.3 Prime and Claude Opus 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-opus-5.5.
Models and publishers
GLM 5.3 Prime · Claude Opus 5.5 · All Z.ai models · All Anthropic models
More comparisons
Claude Opus 5.5 vs GPT-6.1 Sol · Claude Opus 5.5 vs Claude Sonnet 5.5 · DeepSeek V4.1 Flash vs Claude Opus 5.5 · DeepSeek V4 Pro vs Claude Opus 5.5 · All comparisons