GLM 5.3 Flash vs Kimi K3: price, context window and capabilities
GLM 5.3 Flash (z-ai/glm-5.3-flash) from Z.ai and Kimi K3 (moonshotai/kimi-k3) from MoonshotAI are both multimodal language models on the OceanToken API. GLM 5.3 Flash costs less per token than Kimi K3: $0.15 against $3.00 per 1M input tokens (95% less) and $0.50 against $15.00 per 1M output tokens (97% less). Both have a 1.05M-token context window (1,048,576 tokens). Both support tool calling, reasoning, structured outputs, image input and video input.
Side by side
| Spec | GLM 5.3 Flash | Kimi K3 |
|---|---|---|
| Model | GLM 5.3 Flashz- | Kimi K3moonshotai/ |
| Publisher | Z.ai | MoonshotAI |
| Kind | Text, vision & video | Text, vision & video |
| Context window | 1.05M tokens1,048,576 | 1.05M tokens1,048,576 |
| Input price | $0.15 / 1M tokens | $3.00 / 1M tokens |
| Output price | $0.50 / 1M tokens | $15.00 / 1M tokens |
| Cached input price | $0.03 / 1M tokens | $0.30 / 1M tokens |
| Inputs | text, images and video | text, images and video |
| Outputs | text | text |
| Tool calling | Yes | Yes |
| Reasoning | Yes | Yes |
| Structured outputs | Yes | Yes |
About these prices
Which should you choose?
- Choose GLM 5.3 Flash to spend less per token: 95% less for input and 97% less for output than Kimi K3.
- Context size does not separate them: both hold about 1.05M tokens.
- Both list the same capabilities: tool calling, reasoning, structured outputs, image input and video input.
- 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 Flash Kimi K3
Frequently asked questions
Which is cheaper, GLM 5.3 Flash or Kimi K3?
GLM 5.3 Flash. GLM 5.3 Flash costs less per token than Kimi K3: $0.15 against $3.00 per 1M input tokens (95% less) and $0.50 against $15.00 per 1M output tokens (97% 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 Flash or Kimi K3?
Neither. Both have a 1.05M-token context window (1,048,576 tokens).
Can I call both GLM 5.3 Flash and Kimi K3 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-flash or moonshotai/kimi-k3.
Models and publishers
GLM 5.3 Flash · Kimi K3 · All Z.ai models · All MoonshotAI models
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