ThumbSignal scores a YouTube thumbnail and its title together, before you publish — a grade, twelve sub-scores, and alternative titles worth testing. No account needed.

Why it exists

Packaging decides whether a video gets opened, and it is the part creators judge worst. You have stared at your own thumbnail for an hour, at full size, on the machine you made it on — the one condition no viewer will ever see it in. ThumbSignal is a second opinion with no stake in the answer, and it cannot be talked round.

How the score is produced

A vision model looks at the actual image — not the filename, not your description — and reports what survives at feed size: whether the face reads, whether small text stays legible, whether anything competes for the eye. The title is scored separately, partly by plain rules that need no model. The two are combined across twelve dimensions, from readability and emotional pull to curiosity gap, promise clarity and clickbait risk, and then into one global score and a letter grade.

Every result records the version of the pipeline that produced it, so a score that moves can be traced to a change we made rather than to the model having a different day. A regression gate checks that on every build.

What the score is not

It is not a prediction of views. Nothing here can see your competition, your audience, or the moment you publish into, and any tool claiming otherwise is guessing with more confidence than its data allows. Read the score as a reading on the packaging alone — the part you still control — and the sub-scores as the reason for it. Sometimes the honest answer is that the score is wrong and you should publish anyway.

Where your image goes

Analysis runs inside the European Union, on servers in Ireland. While you are signed out, your thumbnail and title are used to produce your result and then discarded — nothing is kept. Nothing you submit trains any model, and nothing is sold. The full detail is in the privacy policy.

Who publishes it

ThumbSignal is built and run by one independent person in France. It is not affiliated with, sponsored by, or endorsed by YouTube or Google, and it has no relationship with any channel it scores. The site carries advertising, which is what pays for the servers and the model calls.

Contact

Corrections, bug reports and disagreements about a score all go to the same place, and all get read. Use the contact form, or write to contact@thumbsignal.com.