ModelRefs / Vision-Language Model (VLM) — AI Glossary

Vision-Language Model (VLM) — AI Glossary

A model that accepts both image (and optionally video) and text inputs within a single unified context. 2 Vision are VLMs. Also called VLM or vision model.

Overview

GPT-4o, Claude 3.5 Sonnet, Gemini 2.5 Pro, and Llama 3.2 Vision are VLMs. The dominant architecture: a vision encoder (ViT) projecting image patches into the LLM's token embedding space. Enables OCR, chart understanding, image Q&A, and visual agent tasks.

Reference details

Topicmultimodal
Also known asVLM, vision model, multimodal LLM
Last reviewed2026-06-24

Example: It infers the number, it does not read it

Asked for a value from a table screenshot, a VLM produces the most probable token given the image representation — which is inference, not extraction. On crisp printed text that is usually right. On a low-resolution scan, a handwritten digit, or a bar without a printed label, it will still return a confident number, because the model has no mechanism for saying “those pixels are ambiguous”. A dedicated OCR engine returns a per-character confidence you can threshold. The practical pattern for documents is to use both: OCR for exact strings, the VLM for layout, structure and meaning.

Commonly confused with

A VLM takes images and text in; it is not a diffusion model, which generates images out. It is also narrower than multimodal architecture generally, which spans audio and video — and its scope is what makes the distinction worth keeping: an image-and-text model is not automatically an audio model.

When to use it

Reach for it when:

  • Screenshots, charts, diagrams and documents where layout carries meaning
  • Visual agent work, where the screen is the interface
  • Open-ended questions about an image that a fixed extractor cannot anticipate

Reach for something else when:

  • Character-exact transcription of dense or degraded text — use OCR and check confidence
  • Where extracted numbers feed calculations without a verification step
  • High-volume identical documents, where a trained extractor is cheaper and more reliable

Referenced by

This term is used by the following ModelRefs references:

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Frequently asked questions

What is Vision-Language Model (VLM)?

A model that accepts both image (and optionally video) and text inputs within a single unified context.

Is Vision-Language Model (VLM) the same as VLM?

Yes — VLM, vision model, multimodal LLM are common aliases for Vision-Language Model (VLM).

What concepts are related to Vision-Language Model (VLM)?

Closely related concepts include llm, multimodal, computer use.