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Preset is pre-configured
This page opens with the target resolution locked to 3840×2160px (16:9), perfectly tuned for YouTube.
YouTube Thumbnail Size
YouTube now recommends thumbnails as large as possible, with 3840×2160 as its current reference size and a minimum width of 640px. Resize to exactly 3840×2160px in your browser — nothing is uploaded.
Size3840 × 2160pxRatio16:9PlatformYouTube
Resize to 3840 × 2160px
Crop, scale, and export in PNG, JPG or WebP
Drop images here, or click to choose files
Processed locally in your browser · Zero server uploads
ReadsPNG, JPG, WebP, GIF, BMP, SVG, AVIF, ICO, HEIC, TIFF, JPEG XL
WritesPNG, JPG, WebP
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Client-Side Architecture
How resizing to 3840 × 2160px works
Resizing is averaging: turning nine source pixels into one, several million times over. Which pixels get averaged, and in what colour space, is the whole difference between a sharp result and a soft, slightly darkened one. This resizer decodes 11 input formats — including the HEIC an iPhone actually produces — resamples with Lanczos3 in linear light, and writes PNG, JPG or WebP, all inside this browser tab.
Batch Resize Workflow3840 × 2160px
Drop a batch in, pick Crop to fill or Fit, and every file is resampled to the exact pixel size on your own device — then downloaded one by one or as a single ZIP.
Resize Architecture100% In-Browser Memory Pipeline
Source Image11 formats
HEIC · TIFF · JPG · PNG
Decoded to raw pixels by the same pipeline the converter uses, so iPhone HEIC and scanner TIFF open without a conversion step first.
Engine: libheif / UTIFZero upload
Web Workerwasm
Lanczos3, Linear Light
Cropped first, then resampled with a 3-lobe windowed sinc — with gamma undone before averaging, because averaging sRGB directly renders the result measurably darker.
Off the main thread100% Private
Result.png .jpg .webp
3840 × 2160px
Exact dimensions every time. WebP typically lands under half the size of the equivalent JPG and keeps transparency, which PNG does at roughly twenty times the bytes.
Single file or ZIPDirect export
End-to-end local architecture: files are processed strictly within your device’s memory and never leave your computer or phone.
For the full walkthrough — why downscaling in sRGB darkens a photo, what Lanczos3 actually does, and how HEIC now opens without a conversion step — read How the Image Resizer works.
Original image vs. 16:9 output
A visual example of the tool's center-crop behavior.
Original example1:1 source
Thumbnail crop16:9
How to resize an image for YouTube Thumbnail
Resize your image to exact 3840×2160px dimensions in three simple steps:
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Upload and choose mode
Drop your image into the tool. Choose "Crop to fill" for exact borderless coverage or "Fit (pad)" to preserve the entire image with background padding.
03
Instant local export
Preview the result in real time and download as high-quality PNG or optimized JPG. No files are uploaded to any server.
Platform Specifications
About the YouTube thumbnail size
The practical preset for a YouTube thumbnail is 3840×2160 pixels (16:9). Uploading at the right dimensions keeps your image sharp and prevents YouTube from cropping or compressing it in unexpected ways. If your photo is a different shape, use the image resizer above to crop or pad it to exactly 3840×2160 before uploading.
Continue with another image tool
After checking an image, choose a tool for the change you need. Each tool has a different purpose.
Compress Images to KB or MB
Reduce file size to fit a KB or MB limit. Compression may also reduce pixel dimensions to reach your target.
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Image Format Converter
Change the image file format, such as PNG to JPG or WebP. This is different from converting pixels to print units.
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Metadata Remover
Need to strip or edit EXIF before sharing? Open Metadata Remover to remove GPS, camera data and other hidden fields.
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Image Size Finder
Check pixel width, height, megapixels and aspect ratio instantly for one image or a full batch.
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Related image presets
Explore more standard sizes for YouTube and other popular platforms.
Popular platform sizes
Frequently used dimensions across major networks:
YouTube Thumbnail FAQ
What size is a YouTube thumbnail?
The recommended YouTube thumbnail size is 3840×2160 pixels, an aspect ratio of 16:9. YouTube now recommends thumbnails as large as possible, with 3840×2160 as its current reference size and a minimum width of 640px.
What is the aspect ratio for a YouTube thumbnail?
16:9 (3840×2160). Matching this ratio avoids unwanted cropping when YouTube displays your image.
How do I resize my image to 3840×2160?
Drop your image into the tool above. "Crop to fill" scales and center-crops to exactly 3840×2160; "Fit (pad)" keeps the whole image and adds padding. Then download as PNG or JPG. Everything runs in your browser — nothing is uploaded.
PNG or JPG for YouTube?
Use PNG for graphics, logos and text (lossless, supports transparency). Use JPG for photos to get a smaller file. This tool exports both.
Free & Private In-Browser Tool
Resize to 3840×2160 Online Now
Fast, 100% private, and completely free in-browser resizer. Crop or fit your images to exactly 3840×2160 pixels for YouTube Thumbnail in seconds.