MyThumbTester guide
Check title contrast in a Shorts preview
Use the Shorts preview to inspect whether a title remains readable over a local thumbnail without treating it as a performance forecast.
Review the title against the image, not a blank background
Use the Shorts preview when the title sits over the thumbnail image. In MyThumbTester, choose the same local image and title, then check the bottom overlay where the title actually appears. If the words blend into the bright or detailed part of the image, revise the image crop or simplify the visible area before adding more words.
This is a reproducible implementation-derived check. MyThumbTester’s Shorts renderer places the title in white over a bottom dark gradient, limits it to two lines, and reserves space at the right for action controls. It checks visible contrast in that illustrative layout, not click-through rate, ranking, or views.
Keep the first line readable near the lower edge
The lower part of a thumbnail may contain faces, captions, or scenery. Read the first title line at the rendered size. If its important noun or verb falls on a busy patch, move the wording earlier, choose a shorter phrase, or change the image composition so the gradient has a calmer area behind the text.
Do not judge this from the original full-size image alone. A high-resolution image can look clear before the layout adds a title, gradient, and action-control area.
Compare one image revision at a time
Keep the title fixed and make one image revision: move the subject, reduce bottom detail, or create more separation between the lower background and the title area. Then switch back to the same Shorts preview and record the visible result.
Export the preview PNG after the title remains readable. The export records the presentation you inspected; it is not evidence of audience response.
What this preview cannot measure
A Shorts preview cannot tell you whether a viewer will watch, whether the video will be distributed, or how many views it will receive. Use it to inspect title contrast and composition in MyThumbTester’s illustrative vertical layout.