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GLM 4.6V Flash

zhipuzhipu/glm-4.6v-flash

Zhipu AI GLM 4.6V Flash β€” free-tier vision model supporting image, video, and document understanding.

GLM-4.6V-Flash is Zhipu AI's (Z.ai) free-tier, lightweight vision-language model released on December 8, 2025. It is the 9B-parameter member of the GLM-4.6V series β€” the other being the 106B Mixture-of-Experts flagship β€” and is optimized for local deployment and low-latency applications. Both models share a 128K-token context window trained natively on long multimodal sequences, enabling a single-pass read of roughly 150 pages of dense documents, 200 slide pages, or one hour of video. Weights are open-sourced on Hugging Face under the THUDM / Z.ai model family.

The defining technical advance in GLM-4.6V-Flash is native multimodal Function Calling β€” a first for the GLM vision family. Traditional multimodal tool use converts images to text before passing them to tools, losing spatial and color information. GLM-4.6V-Flash routes images, screenshots, and document pages directly as tool inputs and can consume visual tool outputs (charts, rendered web pages, search image grids) inside the same reasoning chain. For TheRouter operators, this makes GLM-4.6V-Flash the go-to free option for vision-driven agentic pipelines: it accepts image, video, and PDF inputs and responds with text via the standard OpenAI-compatible /v1/chat/completions endpoint.

Best for
  • β€’ Multimodal agentic pipelines at zero cost: native Function Calling lets the model act on visual inputs directly β€” screenshot-to-action, chart-reading-to-tool-call β€” without lossy image-to-text conversion steps
  • β€’ Long-document and video understanding: the 128K context window processes ~150 pages, 200 slides, or one hour of video in a single pass, making it suitable for financial analysis, report summarisation, and meeting review at no per-token cost
  • β€’ Frontend screenshot-to-code workflows: the model is tuned for pixel-accurate HTML/CSS/JS reconstruction from UI screenshots and supports natural-language-driven visual edits; free tier eliminates per-call cost in iterative design loops
  • β€’ Chinese-language visual tasks: GLM-4.6V-Flash is trained on bilingual Chinese-English corpora with strong coverage of Chinese document layouts, forms, and visual content common in enterprise and government workflows
  • β€’ Local and edge deployment: the 9B dense architecture runs on a single consumer GPU (tested with vLLM β‰₯ 0.12.0 and SGLang β‰₯ 0.5.6); ideal when data residency or latency constraints preclude cloud API calls
Reach for something else if
  • β€’ Pure-text reasoning tasks: by the team's own admission, text-only QA performance lags behind the vision-focused training priorities; use zhipu/glm-4-flash or a dedicated text model for pure language workloads
  • β€’ Exact counting and fine-grained object identification: known limitations include counting accuracy and identifying specific individuals β€” critical-accuracy tasks should be routed to a model without these known gaps or validated via post-processing
  • β€’ High-volume production workloads requiring SLA guarantees: the free tier carries no formal SLA; route to a paid VLM (zhipu/glm-4.6v or zhipu/glm-4.6v-flashx) for business-critical pipelines
  • β€’ Image generation or editing: GLM-4.6V-Flash is a vision-language model (text + image β†’ text) and produces no image output; use zhipu/cogview-4 or zhipu/cogview-3-flash for text-to-image tasks
Context Length
131K
Max Output
16K

Modalities

textimagevideopdf→text

Capabilities

Vision

Pricing Breakdown

Pricing not available.

Supported Parameters

temperaturemax_tokenstop_ptoolstool_choicestop

Specifications

Release date2025-12-08huggingface.co β†—verified
Parameter count9B (dense)huggingface.co β†—verified
ArchitectureDense transformer (GLM-V family); part of the GLM-4.6V series alongside the 106B MoE flagshiphuggingface.co β†—verified
Context window128K tokens (131,072) β€” trained natively at this lengthdocs.z.ai β†—verified
Max output tokens16,384 tokenshuggingface.co β†—verified
Input modalitiesText, image, video, PDF (all accepted in a single request)docs.z.ai β†—verified
Output modalityText only (no image generation)docs.z.ai β†—verified
PricingFree β€” $0 per token (input and output) via TheRouter and the Z.ai platformdocs.z.ai β†—verified
Native Function CallingYes β€” first in the GLM Vision family; images and visual tool outputs pass natively without text conversionhuggingface.co β†—verified
Training cutoffNot publicly disclosedunknown
LicenseGLM-4 Model License (Z.ai / THUDM) β€” open weights; commercial use permitted per license termshuggingface.co β†—to verify
Local deployment supportvLLM β‰₯ 0.12.0; SGLang β‰₯ 0.5.6 (preferred for video tasks); Transformers β‰₯ 5.0.0rc0huggingface.co β†—verified
Recommended decoding parameterstop_p=0.6, top_k=2, temperature=0.8, repetition_penalty=1.1, max_new_tokens=16384huggingface.co β†—verified

API Usage Examples

Use the global api.therouter.ai endpoint shown below for new integrations; the legacy China accelerated endpoint is retired.

cURL
curl https://api.therouter.ai/v1/chat/completions   -H "Content-Type: application/json"   -H "Authorization: Bearer $THE_ROUTER_API_KEY"   -d '{
    "model": "zhipu/glm-4.6v-flash",
    "messages": [
      {"role": "user", "content": "Summarize the key points from this input."}
    ]
  }'

Vision chat completion (image / video / PDF input)

GLM-4.6V-Flash is accessible through the standard OpenAI /v1/chat/completions endpoint at api.therouter.ai. Pass images as image_url content blocks, exactly as you would with GPT-4o. The model supports text, image, video, and PDF inputs in a single request. Function Calling works via the standard tools / tool_choice parameters β€” images and visual tool outputs are handled natively. The API is free; no credits are consumed.

cURL
# Image understanding β€” free via TheRouter
curl https://api.therouter.ai/v1/chat/completions \
  -H "Authorization: Bearer $THEROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "zhipu/glm-4.6v-flash",
    "messages": [
      {
        "role": "user",
        "content": [
          {
            "type": "image_url",
            "image_url": { "url": "https://therouter.ai/assets/vision-sample.png" }
          },
          {
            "type": "text",
            "text": "Summarise the key trends shown in this chart."
          }
        ]
      }
    ],
    "max_tokens": 1024
  }'

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News & changes

2025-12-08

Z.ai releases GLM-4.6V series with native multimodal Function Calling

Zhipu AI (Z.ai) open-sourced the GLM-4.6V series β€” a 106B MoE flagship and the 9B dense GLM-4.6V-Flash β€” both with 128K context and native multimodal tool use. The Flash variant is free via API and is positioned for local and low-latency deployment.

re-authored by TheRouterhuggingface.co β†—

Frequently asked

Is GLM-4.6V-Flash genuinely free, or will it start charging?

As of June 2026 the model is priced at $0 per token (input and output) on both the Z.ai platform and via TheRouter. Pricing is set by Zhipu AI and may change; standard rate limits and content moderation apply regardless of tier. Monitor the Z.ai pricing page for any updates.

What is the difference between GLM-4.6V-Flash and GLM-4.6V-FlashX?

Both are 9B lightweight versions of the GLM-4.6V series. GLM-4.6V-Flash is the free-tier variant with no formal SLA. GLM-4.6V-FlashX is a paid variant (Β₯0.05/M input tokens, Β₯0.30/M output tokens as of June 2026) that offers SLA-backed reliability suitable for production workloads. Choose Flash for prototyping and cost-free pipelines; choose FlashX when you need guaranteed uptime.

How does native multimodal Function Calling differ from standard tool use?

In standard LLM tool use, images must be described in text before being passed as tool arguments β€” losing spatial, color, and layout information in the process. GLM-4.6V-Flash routes images, screenshots, and document pages directly as tool inputs (via URL references) and can process visual outputs returned by tools β€” such as charts, rendered web pages, or image search results β€” as part of the same reasoning chain. The API surface is identical to standard OpenAI tool calling; the multimodal capability is handled transparently by the model and the Z.ai / TheRouter layer.

How much long-context content can GLM-4.6V-Flash actually process?

The model's 128K token context window was trained natively (not extended post-hoc), which means it can sustain coherence across the entire window. The Z.ai team reports practical equivalents of ~150 pages of dense documents, 200 slide pages, or one hour of video in a single inference pass, because visual pages are encoded as tokens by the visual encoder. Maximum output is capped at 16,384 tokens per request.

What are the known limitations of GLM-4.6V-Flash I should account for in production?

The Z.ai team explicitly acknowledges the following in the model card: (1) pure-text QA performance is weaker than the visual capabilities, because this training cycle prioritised multimodal scenarios; (2) the model may occasionally over-think or repeat itself on complex prompts; (3) in some cases it restates the answer at the end of a response; (4) counting accuracy and identification of specific individuals remain imperfect. For free-tier, non-SLA workflows these are acceptable trade-offs. For production paths where any of these matter, validate outputs carefully or route to a paid model.

Fact ledger β€” every claim on this page traces here
sourceURLretrieved
Release datehuggingface.co β†—2026-06-09verified
Parameter counthuggingface.co β†—2026-06-09verified
Architecturehuggingface.co β†—2026-06-09verified
Context windowdocs.z.ai β†—2026-06-09verified
Max output tokenshuggingface.co β†—2026-06-09verified
Input modalitiesdocs.z.ai β†—2026-06-09verified
Output modalitydocs.z.ai β†—2026-06-09verified
Pricingdocs.z.ai β†—2026-06-09verified
Native Function Callinghuggingface.co β†—2026-06-09verified
Training cutoffβ€”β€”unknown
Licensehuggingface.co β†—2026-06-09to verify
Local deployment supporthuggingface.co β†—2026-06-09verified
Recommended decoding parametershuggingface.co β†—2026-06-09verified
Z.ai releases GLM-4.6V series with native multimodal Function Callinghuggingface.co β†—2026-06-09verified
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