What is Video Alt Text?
Video alt text concisely describes a video’s essential visual subject or purpose for people who cannot perceive it. Because HTML video lacks an alt attribute, the description appears in nearby accessible content or player metadata.
How Video Alt Text works
A textual alternative for video communicates the visual purpose or essential information that surrounding prose, dialogue, and captions do not already provide. Its scope depends on context: a decorative loop may need no additional description, while a silent demonstration may need a concise explanation or a fuller transcript. Since the media element has no image-style alt field, authors must deliberately associate or position the text. This accessibility copy is prepared with player metadata and editorial review.
A metadata reader parses known structures and can derive additional properties from the encoded content. The workflow then validates and normalizes fields before using them for search, routing, naming, filtering, or access decisions.
Metadata can be embedded in a file, stored beside it, or derived during analysis. Track its source and normalization rules, and decide which fields are authoritative, searchable, privacy-sensitive, or safe to copy into derivatives.
Key facts
- 1An accessible name for the player identifies the control or title but does not necessarily describe the video’s visual content; naming and content alternatives solve separate problems.
- 2Captions represent speech and important sounds, whereas a visual description conveys actions, appearance, diagrams, or on-screen changes that cannot be inferred from the audio.
- 3Nearby descriptive text can be programmatically associated with the player through an accessible description, but duplicate visible and hidden copies may cause screen readers to announce it twice.
When Video Alt Text matters
Provide a description when visuals convey information that dialogue or captions omit. Without one, screen-reader users may miss the video’s purpose even when playback controls are accessible.
- Filtering files by dimensions, duration, codec, MIME type, language, or detected content.
- Building catalogs with searchable descriptions, rights, locations, and relationships.
- Driving output paths, transformation parameters, moderation, and retention rules.
Working with metadata at scale
Guidance that holds across every metadata term in this glossary, not just Video Alt Text.
What you gain
- Structured metadata makes media searchable, filterable, and automatable.
- Technical properties let workflows choose valid transformations before processing.
- Provenance and rights fields support governance throughout an asset’s lifecycle.
What it costs
- Copying all metadata preserves context but can leak private or obsolete information.
- Derived labels scale classification but carry confidence limits and model bias.
- Rigid schemas improve consistency while making novel or vendor-specific fields harder to retain.
Answer these before production
- 1Distinguish supplied metadata from values detected or derived during processing.
- 2Normalize units, time zones, encodings, and controlled vocabularies at ingestion.
- 3Remove sensitive fields before exposing files or metadata to another audience.
How Transloadit helps with Video Alt Text
When Video Alt Text is relevant to your workflow, you can hand the surrounding metadata work to Transloadit instead of maintaining the processing stack yourself. Transloadit reads technical metadata as files enter a workflow and exposes it to later Steps and Assembly Variables. It can also write selected metadata into supported output files.
Support for a specific codec, container, parameter, or combination can vary by Robot and processing stack. Check the linked documentation for the exact inputs and outputs available for your use case.