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Z.ai: GLM 5.3 Flash

glm-5.3-flash

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GLM 5.3 Flash costs $0.130 per million input tokens and $0.390 per million output tokens, supports 1.05M context, and is available through the OpenAI-compatible API.

Ox-alpha out of stealth! GLM-5.3 Flash is Z.ai's first natively multimodal GLM-5 model, with 320B total parameters and just 18B active parameters for efficient coding, agentic work, and precise 1M-token context. Its hybrid sparse-and-linear attention architecture helps it outperform GLM-5.2 at one-tenth the price while approaching Claude Opus 4.8 on coding and agentic benchmarks.

Modalities

Text + Image + Video → Text

Input / output price

$0.130 / $0.390 per 1M

Context

1.05M · max output 131K

Capabilities

ReasoningVisionTool callingLong contextOpen weights

Pricing

Billed per token actually used and deducted from your credits.

ItemUSD per 1M tokens
Input$0.130
Output$0.390
Cached input$0.0325

Calculator

Drag the sliders to estimate what this model will cost.

Per request
$0.00070
Per day
$0.3510
Per month (30 days)
$10.53

GLM 5.3 Flash: input $0.13/M · output $0.39/M · cached input $0.0325/M

Request with these settings
curl https://api.geniusrelaygpt.com/v1/chat/completions \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "glm-5.3-flash", "max_tokens": 800,
       "messages": [{"role": "user", "content": "…"}]}'

Code samples

OpenAI-compatible. Set the base URL to https://api.geniusrelaygpt.com/v1 and the model to glm-5.3-flash.

curl https://api.geniusrelaygpt.com/v1/chat/completions \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "glm-5.3-flash",
    "stream": true,
    "messages": [{"role": "user", "content": "Hello"}]
  }'

Use it in a client: Cursor · Cline · SillyTavern · Codex

Parameters

Common OpenAI parameters can be passed as-is.

temperaturetop_pmax_tokensstreamstoppresence_penaltyfrequency_penaltyseed

FAQ

How is GLM 5.3 Flash billed?
Input is $0.130 and output is $0.390 per million tokens; cached input is $0.0325. The charge for every request is listed in Usage Logs in the console.
How long is the context window?
1.05M tokens. In a long conversation every turn is billed for the full input, so keep the history under control.
Does it support streaming?
Yes. Add "stream": true to the request to receive server-sent events in the OpenAI format.
GLM 5.3 Flash API pricing · GeniusRelay