How Do I Write Good Alt Text for Educational Images?
Write educational image alternatives from the real source and task. Review charts, diagrams, screenshots and decorative treatment, and provide fuller explanations for complex content.
Useful educational alternatives describe the information an image communicates in context. A description of appearance alone may omit the relationship the student needs to understand.
Read the source before writing
Inspect the figure, caption and lesson objective. For a chart, verify axes, units, values and the relevant trend. For a diagram, describe relationships and sequence. For a screenshot, explain the relevant state or action. Do not add plausible values, names or processes that the source does not establish.
For example, a hypothetical description “two bars comparing enrollment by year” identifies a chart but may need the actual years and values to serve the lesson. That example is illustrative and contains no measured institutional data.
Match the alternative to the purpose
A photograph explaining equipment placement needs different detail from a decorative photograph beside an unrelated paragraph. Use the format's supported decorative treatment when appropriate. For an image acting as a link or control, convey the function.
Provide fuller access when needed
Complex figures can need a brief identifier with an accessible longer explanation or relevant data representation. The explanation must preserve the task's information. Equations and chemical structures may need specialist review and an evaluated representation; fluent prose alone cannot establish equivalence.
W3C's image guidance provides purpose-based examples. Choose length and delivery according to the actual content, rather than a universal character limit.
Review the saved result
Check the description in the final document or platform and test how the user reaches associated detail. Generated alternatives need source and teaching-context review, even without an uncertainty flag.
Aelira Core is beta software. Supported workflows can apply eligible partial fixes and record outcomes, but some inputs need manual work or cannot produce a downloadable remediated file. Review the actual saved output, unresolved findings and content preservation before publication. Automated scores describe implemented checks rather than accessibility conformance. Inspect the public source and release documentation and evaluate a representative authorized sample before planning a rollout.
Aelira Team
•Accessibility EngineersThe Aelira team is building beta accessibility tools for higher education. Institutions can evaluate selected checks and partial fixes on their own files, with human review required before publication.
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