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Free Image Resizer Online

Set exact dimensions, scale by percentage, or pick a social media preset. Lanczos algorithm for crisp results. No signup, no watermarks.

Drop your image here

JPG, PNG, WEBP, GIF, BMP - Up to 20 MB

Original image preview
Original: - -
Output: -  •  -

Resizing image…

Resize Settings
Resize Mode
Width × Height (px)
Width
Height
Output size -
Scale -
Output Format
Quality 85

How to Resize an Image Online

Upload your image, choose a resize mode, and click Resize & Download. The tool uses the Lanczos algorithm - The same high-quality resampling used in professional image editors - To keep edges sharp and colours accurate when scaling down. For upscaling beyond the original resolution, results will be smooth but less sharp (no algorithm can invent new detail).

All resizing happens in your browser. Your image is only sent to our server when you click Download, purely to ensure the correct file format and compression settings are applied. Images are never stored or shared.

Social Media Image Size Guide

PlatformUseSize (px)Aspect Ratio
InstagramSquare Post1080 × 10801:1
InstagramStory / Reel1080 × 19209:16
InstagramLandscape Post1080 × 5661.91:1
X (Twitter)Post Image1200 × 67516:9
X (Twitter)Header / Banner1500 × 5003:1
FacebookPost Image1200 × 6301.91:1
FacebookCover Photo820 × 3122.63:1
YouTubeThumbnail1280 × 72016:9
YouTubeChannel Art2560 × 144016:9
LinkedInPost Image1200 × 6271.91:1
LinkedInBanner1584 × 3964:1
PinterestPin1000 × 15002:3
TikTokVideo Cover1080 × 19209:16

JPG vs PNG vs WebP - Which Format to Choose

JPG - Best for photos. Lossy compression keeps file sizes small with minimal visible quality loss at quality 80+. Use for anything with smooth color transitions or natural colours.

PNG - Best for logos, screenshots, and images with sharp edges or transparency. Lossless compression means no quality loss but larger files than JPG.

WebP - Best for web use. 25–35% smaller than JPG at equivalent quality, supports transparency, and is now supported by all modern browsers. The smart default for any image going on a website.

Frequently Asked Questions

Does resizing reduce image quality?
Downscaling (making smaller) generally preserves quality very well. This tool uses the Lanczos algorithm - The gold standard for image resampling - Which minimises aliasing and keeps edges crisp. Upscaling beyond the original resolution will always be less sharp because no algorithm can invent new detail. Use our AI Upscaler if you need to genuinely enlarge an image.
What image formats can I upload?
You can upload JPG, PNG, WEBP, GIF, and BMP images up to 20 MB. The output can be saved as JPG, PNG, or WebP with quality control for JPG and WebP.
Does the tool keep the aspect ratio?
Yes, the aspect ratio lock is on by default in Dimensions mode. When you change the width, the height auto-updates to match the original proportions. Click the lock icon between the W and H inputs to disable it and set any arbitrary dimensions.
What is the maximum output size?
You can upload images up to 20 MB, and output dimensions are capped at 8000 × 8000 px to prevent excessive processing time on the server.
Is my image stored or shared?
No. The preview and resize happen entirely in your browser using JavaScript. Your image is only sent to our server when you click Download, solely to apply the correct format and compression settings. It is immediately discarded afterwards - Never stored, indexed, or shared.
What is the difference between percentage and dimension resize?
Percentage mode scales the image relative to its original size - Useful when you want to halve or quarter an image without knowing the exact pixel dimensions. Dimension mode lets you target an exact output resolution in pixels, which is what most social media platforms require.

Practical Image Resizing Workflow

Resize for the place the image will actually appear. A 4000px camera photo does not make a 900px content column look better, but it does make the page heavier.

Pick the right web size
Common widths are 1200px for large content images, 1600px to 1920px for hero images, and 600px to 900px for inline article images. After resizing, use image compression for faster delivery.
Set the crop before the resize
Square posts, stories, thumbnails and banners all crop differently. If you need a square product image or avatar, use the Image Cropper first so the important subject keeps more pixels.
Check CMS and marketplace previews
Some platforms automatically crop thumbnails, while others display the exact ratio you upload. A consistent resize workflow prevents awkward cuts in grids, related posts, product cards and mobile previews.
Create a reusable size system
Instead of guessing every time, keep a small set of standard sizes: one for thumbnails, one for article images, one for product detail pages and one for hero banners. This keeps layouts consistent and makes future optimization faster.
Resize differently for social and email
For social posts, set the crop ratio before resizing so the subject stays visible in previews. For email, keep images modest, usually around 600px to 1200px wide, because many email clients clip, proxy or compress large files.
Check sharpness after export
After resizing, view the file at the final size. If it looks soft, go back to the original source and export again instead of repeatedly resizing the already exported image.
Keep one original master
Do not resize the same file again and again. Each export can soften details, especially when changing formats. Save final files with clear names such as product-name-1200.webp or hero-image-1920.jpg.
Upscale only when the source is too small
If the original image is too small for the placement, use the AI Image Upscaler before final resizing. If the image is already large enough, resize down instead of making it bigger.