Understand .SUB Files

All you need to confidently work with the image/vnd.dvb.subtitle format.

image

.sub

Raster or vector imagery used in design systems and web experiences.

MIME TYPE

image/vnd.dvb.subtitle

Best for

Brand assets, UI elements, product screenshots, and creative deliverables.

Opens with

Preview, Figma, Adobe Photoshop

Registered by

iana

Make the format work for you

Great for packaging consistent visuals your marketing and product teams can reuse instantly.

Optimize dimensions and compression so render blocks don't slow down page loads.
Images are usually safe. Be mindful of metadata if you're sharing externally.
Add a short README alongside the file so collaborators know when to use it and how to preview it.

Quick operational checklist

Share confidently. Include sample content and note the expected software version so reviewers open it correctly.
Stay searchable. Tag uploads with image/vnd.dvb.subtitle or .sub in your knowledge base so teammates find the right asset fast.
Plan conversions. If recipients cannot open .sub, export a lightweight PDF or screenshot alternative for quick review.

Explore neighbours to decide whether .sub is the best hand-off or if a sibling suits your workflow better.