Image Resizer

Resize images to any width or height in your browser. Supports JPG, PNG, WebP and HEIC inputs.

ToolLast updated ·Reviewed by the OnlineFileConverter team

Drop or click to select an image

About this tool

Resizing an image is one of the most common content tasks — preparing photos for a website, shrinking a screenshot before pasting it into a document, or hitting an exact pixel dimension required by an upload portal. Our Image Resizer runs entirely in your browser using the HTML5 canvas, so even very large originals are processed without ever being uploaded.

You can set width, height, or both — with an option to lock the aspect ratio so the image isn't stretched. Output format can be JPG (smallest for photos), PNG (lossless, preserves transparency), or WebP (best of both worlds for modern browsers).

Downscaling produces sharp, high-quality results. Upscaling is inherently limited — a 500-pixel-wide image can't gain new detail when stretched to 2000 pixels — so for the best results, always start from the largest version you have.

Why use it

  • Set exact width and/or height in pixels.
  • Lock aspect ratio with a single toggle.
  • Choose JPG, PNG, or WebP output.
  • 100% browser-based — no upload, no signup.

How to use it

  1. 1
    Upload your image

    Drop a JPG, PNG, WebP, or HEIC image into the upload area.

  2. 2
    Set dimensions

    Enter a width (and height if you've unlocked aspect ratio). Pick your output format.

  3. 3
    Resize and download

    Click 'Resize image'. The new version downloads — your original is untouched.

Common use cases

  • Hitting exact dimensions required by job portals or government uploads.
  • Preparing product photos for an e-commerce store.
  • Shrinking screenshots before pasting into Word, Notion, or chat.
  • Generating Open Graph or Twitter card images at 1200×630.
  • Creating thumbnails for a blog or newsletter.
  • Reducing photo file size by halving the dimensions.

Tips for best results

Halving width quarters the file size

Image file size scales with pixel count, not linear dimension — a 50% resize is usually a 75% file size drop.

Keep aspect ratio locked unless you mean to stretch

Unlocking aspect ratio is for thumbnails and banners; for normal photos, leave it on to avoid distortion.

Use WebP for the web

WebP files are typically 25–35% smaller than JPG at the same visual quality, and every modern browser supports them.

Related tools

Frequently asked questions

Will resizing reduce quality?

Downscaling produces a sharp result. Upscaling is mathematically limited — small images can't gain detail they never had.

Can I keep aspect ratio?

Yes — leave the height empty (or toggle 'lock aspect ratio') and we'll compute it for you.