Thumbnail Preview Tester
Choose an image and compare how it looks inside common social and content thumbnail frames.
A QUICK WALKTHROUGH
How to use this tool
- Choose a local JPEG, PNG, WebP, or GIF image.
- Pick a preset or enter a custom width and height.
- Review the object-fit preview and the exact pixel and aspect-ratio reference.
Local image preview
The selected image is decoded and displayed in this browser. It is not uploaded, stored, or sent to a platform.
Reference sizes, not platform verification
Presets are common starting points for social and content thumbnails. Platforms can change requirements, crop differently, or apply their own safe areas. Treat every size as user-configurable and approximate unless you verify the destination platform separately.
GOOD TO KNOW
Common questions
Does this upload my image?
No. File reading and preview rendering happen locally in your browser.
Are these official platform specifications?
No. Presets are approximate reference sizes. Enter your own dimensions when a destination provides a current requirement.
Will the preview match every platform crop?
No. It uses a local object-fit cover frame to show a common thumbnail treatment; destination interfaces may crop or scale differently.