Thumbnail Preflight

See a thumbnail at the size viewers see it

A thumbnail and a title go in; you see them at true pixel size on the phone feed, desktop home, the suggested sidebar and search, in light and dark, beside other videos.

You give it: One image (PNG or JPEG) and a title
You get back: Four surfaces rendered at real size, the 168-px look, and the objective checks: size, weight, ratio, truncation, what YouTube's UI covers
Where it runs: Runs in your browser

Open Thumbnail Preflight

What you get free

The whole tool: a thumbnail and title on all four surfaces, both themes, every check, the 168-px look.

What it doesn't do

No predicted click-through rate, on purpose: that number cannot be checked. YouTube Studio's Test & Compare runs the real test; this makes sure what you send it is legible and intact.
Surface dimensions are YouTube's layouts as measured in September 2026; the typeface is this page's, not Roboto, so truncation can differ by a character.

What it costs

Thumbnail Preflight is free to use today, and there is nothing to buy. It is planned to be part of the $19/month Avyth subscription, which covers every tool with a recurring job — Invoice Splitter, SlipMatch, FBA Gap Auditor, Article 50 Check and Playback Check — not a separate charge for this one tool — it would add: A side-by-side variant comparison is planned; nothing about the tool is behind a key today.

It isn't built, so there is no checkout on this site and no way to be charged. When it exists it will appear on the updates page, with the date.

If it doesn't work

Email support@avyth.com and the person who built Thumbnail Preflight reads it. If it fails on your file, say what the file looks like — that is usually enough to fix it.

The other tools

All eight, with their limits →