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Thumbnail, Post & Story Sizes

Specs checked against each platform's help · 2026-10-24

YouTube video and Shorts thumbnails, Instagram posts and Instagram Stories side by side: the size to upload, the formats each accepts and its file limit.

Sizes and file limits by platform

Platform & pageOutputSizes (px)FormatsMax file size
YouTube thumbnailThumbnail3840×2160JPG, PNGJPG 50 MB, PNG 50 MB
Mobile thumbnail1280×720*JPG, PNGJPG 2 MB, PNG 2 MB
Shorts thumbnail2160×3840JPG, PNGJPG 50 MB, PNG 50 MB
Instagram postSquare post1080×1080JPG, PNG—
Portrait post1080×1440JPG, PNG—
Landscape post1080×566JPG, PNG—
Instagram storyStory1080×1920JPG, PNG—

* Our pick: no exact size is published for this, so we export one that stays sharp.

Checked against each platform's own help pages. Oldest check: 2026-10-24.

Thumbnails and stories are the two big full-frame images: wide 16:9 for YouTube videos, tall 9:16 for Shorts and Instagram Stories. The table above compares them, with the size to upload, the formats each accepts and its file limit.

Wide or tall

The shape matters more than the pixel count. A 16:9 thumbnail and a 9:16 story share no layout, so crop each one from your source rather than stretching one into the other. Keep the subject and any text in the middle third, which every crop and every device keeps.

File limits

YouTube accepts thumbnails of up to 50MB from a computer but just 2MB from its mobile app. Meta publishes no file limit for organic Stories, so the table shows none.

Frequently asked questions

How do I resize an image to thumbnail and story sizes?

Open the row you need in the table above and drop your image in. Each page crops it to the right shape, 16:9 for video thumbnails or 9:16 for Shorts and Stories, resizes it to the exact size and checks the file limit. You can then download a single file or a ZIP, all without uploading anything.

What size is a YouTube thumbnail?

3840×2160 recommended for videos and 2160×3840 for Shorts, JPG or PNG, up to 50MB from desktop. The YouTube thumbnail maker makes them.

What size is an Instagram Story?

1080×1920 pixels, 9:16, as JPG or PNG, the only Stories size Meta publishes. The Instagram Story resizer makes it from any image.

Can I turn a 16:9 thumbnail into a 9:16 story?

Only by cropping or padding, because the shapes are opposite: a 16:9 image is wide and a story is tall. Cropping keeps a vertical slice of the middle; Contain keeps everything and adds bars above and below. For the best result, design the vertical version separately with the main subject in the centre.

Why is my YouTube thumbnail rejected from my phone?

YouTube allows thumbnails of up to 50MB from a computer but only 2MB when you upload from the mobile app. ImgWrench's thumbnail page makes a smaller 1280×720 mobile version, our own pick, and checks it against the 2MB limit, so you can upload from either.

Are my images uploaded anywhere?

No. Every ImgWrench tool runs entirely in your browser, so your images are resized on your own device and never sent to a server. Nothing is stored or shared. You can check this yourself: open your browser's network tab while you resize and download, and you'll see no image data leave the page.