Image Resizer

Resize images by pixels, percentage, or preset — batch-process in your browser.

ToolFlux's Image Resizer scales JPG, PNG, WebP and AVIF images right in your browser — resize by exact pixels, percentage or preset, keep the aspect ratio, batch a whole folder, and download a ZIP, with nothing ever uploaded.

Your files never leave your device — everything runs in your browser.

    Resize by

    Resize images online — free, private, and in your browser

    Whether you need a profile picture at an exact size, a batch of photos scaled down for a website, or a screenshot trimmed to fit an upload limit, this free image resizer changes the dimensions of JPG, PNG, WebP and AVIF files in seconds. Resize by exact pixels, by a percentage of the original, or with a one-click preset for the longest side. Because every pixel is processed on your own device using your browser’s built-in image engine, your photos stay completely private — nothing is ever uploaded.

    How to resize an image

    1. Add your images Drag your photos onto the box above, or click to choose them from your device. You can add one image or a whole batch.
    2. Choose how to resize Pick a method: exact width and/or height in pixels, a percentage of the current size, or a preset that targets the longest side.
    3. Set your options Keep “Maintain aspect ratio” on to avoid distortion, and tick “Don’t enlarge” if you never want images blown up beyond their original size.
    4. Resize the files Click Resize images and watch the progress bar as each photo is processed in your browser.
    5. Download the results Download each resized image, or click “Download all (.zip)” to save the whole batch at once.

    Three ways to resize, and when to use each

    • Exact pixels. Set a specific width and/or height — perfect when a platform demands precise dimensions, such as a 1080×1080 social post or a 400×400 avatar. Leave one field blank to scale that side automatically.
    • Percentage. Scale by a factor of the current size — 50% halves the dimensions, 200% doubles them. Great when you want “half size” without doing the maths.
    • Preset (longest side). Cap the longest edge at a common web size (1920, 1280, 800, or 640 px) while keeping the aspect ratio. Ideal for preparing a mixed batch of landscape and portrait photos for the web in one go.

    Aspect ratio and upscaling, explained

    Keeping maintain aspect ratio on means your image never looks squashed or stretched: the tool scales width and height together. With it on and only one dimension set, the other is calculated for you; with both set, the image is fitted inside that box. Turn it off only when you genuinely need exact, non-proportional dimensions. The don’t enlarge option is a safety net — enlarging an image can never add real detail, so it only makes pictures look soft and blocky. Leaving this ticked guarantees images are only ever made smaller, never blown up past their original size.

    Resize in your browser, with no upload

    Many “resize image” websites send your files to a server, process them there, and ask you to trust that they delete them. For anything personal — family photos, IDs, screenshots of private information — that is a real privacy risk. This tool runs 100% on your device, so your images are never transmitted, there is no upload size cap, and it keeps working offline once the page has loaded. Want to go further? Shrink the file size with the Image Compressor, change formats with the Image Converter, or convert iPhone photos with HEIC to JPG.

    Frequently asked questions

    Are my images uploaded to resize them?
    No. Resizing happens entirely inside your browser using your device’s own CPU and the Canvas engine. Your photos never leave your device, so they are never seen by us or anyone else.
    Which formats can I resize?
    JPEG, PNG, WebP and AVIF. Each image is re-encoded in its original format at the new size, so a JPEG stays a JPEG and a PNG stays a PNG. To change the format instead, use our Image Converter.
    What is the difference between resizing by pixels, percentage, and preset?
    Exact pixels lets you set a specific width and/or height. Percentage scales the image up or down by a factor of its current size — 50% halves it. A preset scales the image so its longest side matches a common target like 1920, 1280, 800, or 640 pixels, which is handy for the web.
    What does “maintain aspect ratio” do?
    When it is on (the default), the image keeps its original proportions: if you set only a width, the height is calculated automatically, and if you set both, the image is scaled to fit inside that box without distortion. Turn it off to stretch the image to exact dimensions, which can squash or stretch it.
    What does “don’t enlarge” do?
    It prevents the tool from making an image bigger than its original size. If your target is larger than the source, the image is left at its original dimensions instead of being upscaled, which avoids the blurry, blocky look that enlarging always produces.
    Can I resize many images at once?
    Yes. Drop in a whole batch and they are all resized with the same settings. Download each result individually, or click “Download all (.zip)” to grab the entire set in one archive — built in your browser too.
    Will resizing reduce the file size?
    Usually, yes. Fewer pixels means a smaller file, so downscaling typically shrinks the file noticeably. If you specifically want the smallest file at the same dimensions, run the result through our Image Compressor afterwards.
    Does the resizer work offline and on phones?
    Yes to both. Once the page has loaded, all the code it needs is on your device, so you can disconnect from the internet and keep resizing. It also runs in any modern mobile browser on iPhone and Android.