ThumbProofThumbnail guides for video creators
Short, sourced guides that each answer one question about thumbnails, with a link to the free tool that checks it in your browser.
Video Thumbnail Size, Resolution, File Limits and Safe ZonesExact thumbnail sizes for 16:9 videos and 9:16 Shorts, the 2 MB mobile and 50 MB desktop limits, file formats, every feed display size and the safe zones to keep clear.
High-CTR Thumbnail Checklist: 7 Visual Principles That Get NoticedA 7-point thumbnail checklist with pass/fail tests: one focal point, contrast, faces, 3–5 words, color separation, small-size legibility and title pairing. Run it before every upload.
Title Truncation by Device: Pixel Widths, Not Character CountsHow long a video title can be before it is cut off on desktop, mobile, search and sidebar layouts. Why truncation depends on pixel width, not character count, with tables and examples.
Thumbnail Color and Contrast: Standing Out in Dark and Light FeedsHow to make thumbnails stand out in dark and light feeds: brightness ranges, RMS contrast targets, the 4.5:1 text rule, color-vision checks and a squint test, with tables and examples.
Thumbnail Text: How Many Words, How Big, and Where to Put ThemHow many words to put on a thumbnail, how big the text should be, which fonts read at 168×94 and where to place text so the duration badge never covers it. Tables, examples and tests.
Faces and Focal Point: Making One Thing Impossible to MissHow big a face should be in a thumbnail, which expressions read at small sizes, where to place the focal point and how to check it with squint, heatmap and face-detection tests.
Vertical Cover Safe Area: 9:16 Sizes, UI Zones and Grid CropsThe right size for vertical video covers (1080×1920, 9:16), the safe area that UI overlays cover, how 4:5 and 1:1 grids crop the cover, and how to design one that survives every crop.
How to A/B Test Thumbnails Before and After You PublishA step-by-step method to A/B test video thumbnails: build meaningful variants, run a blind pre-test before publishing, read pick rates and reaction times, then confirm with a platform experiment.Related
More free tools and guides
Feed PreviewDesktop, mobile, search and sidebar mockupsA/B Blind TesterMulti-round blind test for 2–4 versionsSafe Zone CheckerDuration badge and overlay inspectorShorts & Reels Cover9:16 shelf, UI zones and grid cropsThumbnail ResizerResize and crop to 1280×720 or 9:16, under 2 MBVideo Thumbnail Size, Resolution, File Limits and Safe ZonesGuideHigh-CTR Thumbnail Checklist: 7 Visual Principles That Get NoticedGuideTitle Truncation by Device: Pixel Widths, Not Character CountsGuide
Video Thumbnail Size, Resolution, File Limits and Safe ZonesGuideHigh-CTR Thumbnail Checklist: 7 Visual Principles That Get NoticedGuideTitle Truncation by Device: Pixel Widths, Not Character CountsGuide