YouTube Thumbnail - Check & Resize Your Image
Check your YouTube video thumbnail image locally, compare measured fields with the dated source, then crop or pad to the recommended canvas and recheck the output.
The original stays on your device. EXIF orientation may be applied by the browser; output is a new PNG.
Recommended export: 3840 × 2160 px. This is a recommendation, not an invented minimum.
Source, scope and uncertainty
Official YouTube video thumbnail source · checked 2026-09-13 · custom video thumbnail; upload-device limits differ.
Desktop and mobile have different upload limits. The 3840 × 2160 canvas is a recommendation; account eligibility is not checked locally.
PASS/FAIL applies to the stated measurable fields. ADVISORY describes a recommendation. UNKNOWN remains unknown; a local pass cannot promise upload acceptance.