Image Resizer

An image resizer changes the pixel dimensions of a photo so it fits exactly where you need it: a social media post, a website banner, an email header or an upload form. Our free tool resizes JPG, PNG and WebP images in your browser, without uploading them anywhere. Enter a width and height in pixels or scale by a percentage, lock the aspect ratio so nothing gets stretched, or pick a ready-made preset for Instagram, Facebook, LinkedIn, YouTube, X or email. Resize a whole batch at once and download the results as JPG, PNG or WebP, individually or as a ZIP.

How to use the Image resizer

1. 1 Add one or more imagesDrop your JPG, PNG or WebP files onto the tool or choose them from your device. Everything is processed locally in your browser.
2. 2 Choose a preset or your own sizePick a preset such as Instagram post (1080 x 1080) or Facebook/LinkedIn share (1200 x 630), or type a width and height in pixels, or scale by a percentage.
3. 3 Keep the aspect ratio lockedWith the lock on, changing the width updates the height automatically so the image keeps its proportions. Unlock it only when you deliberately want a different shape.
4. 4 Pick an output formatSave as JPG for photos that must work everywhere, WebP for the smallest files on websites, or PNG when you need lossless quality or transparency.
5. 5 Download your resized imagesDownload each image on its own, or the whole batch as a single ZIP file ready to upload.

Resizing and compressing are not the same thing

Resizing changes the number of pixels in an image. Compressing changes how efficiently those pixels are stored. Both make files smaller, but resizing usually has the bigger effect, because halving the width and height of a photo leaves a quarter of the pixels.

A modern phone camera produces images around 4000 pixels wide. Almost no web page or social network displays images that large, so the extra pixels are downloaded and then thrown away by the browser. Resizing to the size you actually need first, then compressing if necessary, gives you sharp images with small files. For the compression step, our image compressor offers a quality slider and shows the percentage saved.

Social media image sizes built into the presets

Each platform crops and scales uploads to fit its own layouts. Uploading at the recommended size and shape means you control what is shown instead of leaving it to an automatic crop. The tool includes these presets:

• Instagram post: 1080 x 1080 pixels, a square feed image.
• Instagram story: 1080 x 1920 pixels, a full-screen 9:16 vertical image. Also suits other vertical story formats.
• Facebook and LinkedIn share image: 1200 x 630 pixels, the standard link preview shape used by Open Graph.
• YouTube thumbnail: 1280 x 720 pixels, a 16:9 image.
• X (Twitter) post: 1600 x 900 pixels, a 16:9 landscape image.
• Email header: 600 pixels wide, the width most email templates are designed around.

Getting the aspect ratio right

The aspect ratio is the shape of an image: its width compared with its height. A square is 1:1, a widescreen frame is 16:9 and a phone story is 9:16. When the lock is on, the tool keeps your original ratio, so a landscape photo resized to 1080 pixels wide will come out wider than it is tall rather than square.

If your photo has a different shape from the size you need, crop it first in your phone's photo editor or a desktop editor, choosing the target ratio, and then resize. If you unlock the ratio and force a landscape photo into a square, people and products will look squashed, which is one of the quickest ways to make a post look amateur.

Scaling by percentage is handy when you just want an image smaller and do not care about an exact pixel count, for example 50% to halve a batch of photos before emailing them.

What is the best image size for a website?

There is no single answer, but there is a simple rule: make the image about as wide as the largest space it fills, allowing a little extra for high-resolution screens. On most small business websites built with WordPress, Shopify, Squarespace or Wix, that works out roughly as follows.

• Full-width hero or banner: 1920 to 2000 pixels wide.
• Image inside a blog post or content column: 1200 to 1600 pixels wide.
• Product photos: 1200 to 1600 pixels on the longest side, which leaves room for zoom features.
• Team photos, thumbnails and cards: 600 to 800 pixels wide.
• Logos: as small as looks crisp, often 400 pixels wide or less; SVG is better where your platform allows it.

Image dimensions, page speed and Core Web Vitals

Oversized images are among the most common causes of slow pages flagged in speed tests. When the biggest visible element on a page is a photo, its download time largely decides your Largest Contentful Paint (LCP), the Core Web Vital Google rates as good at 2.5 seconds or under. Serving a 1920 pixel hero instead of a 4000 pixel original can cut that download by several megabytes on its own.

Correct dimensions also help with layout stability. When your HTML includes width and height attributes that match the image's real proportions, the browser reserves the right amount of space before the file arrives, so text does not jump around as images load. That jump is what Cumulative Layout Shift measures.

For the best results on phones, create two or three sizes of important images, for example 800, 1200 and 1920 pixels wide, and list them in the srcset attribute so each device downloads the one it needs. The batch feature makes producing those versions quick.

Private by design: files stay in your browser

The resizer uses your browser's built-in image processing, so photos are never uploaded to MakeItFlow or any other server. That keeps customer photos, staff headshots and unreleased product images under your control, which is simpler under UK GDPR than sending personal data to an unknown online service. It also means there is no upload wait: resizing starts as soon as you add your files.

Sizing images for email newsletters and attachments

Most email templates are built around a content width of about 600 pixels, which is why the tool includes a 600 pixel email header preset. Images much wider than that are scaled down by the email client anyway, but every recipient still downloads the full file, and very large emails can be clipped or load slowly on mobile data.

For crisp results on high-resolution phone screens, some designers export header images at double the width, 1200 pixels, and set the display width to 600 in the template. Either approach works; the important thing is not to drop a 4000 pixel photo straight into a newsletter.

The same thinking applies to attachments. If you are emailing a set of site photos to a client or a surveyor, scaling them to 50% or to 1600 pixels wide keeps plenty of detail for viewing on screen while keeping the total under typical attachment limits. Keep the full-size originals for anyone who needs to print them.

Examples you can copy

Instagram post            1080 x 1080   (1:1)
Instagram story           1080 x 1920   (9:16)
Facebook / LinkedIn share 1200 x 630    (about 1.91:1)
YouTube thumbnail         1280 x 720    (16:9)
X post                    1600 x 900    (16:9)
Email header              600 wide      (height follows image)

Hero / banner        1920-2000 px wide   WebP
Blog content image   1200-1600 px wide   WebP
Product photo        1200-1600 px        WebP or JPG
Thumbnail / card     600-800 px wide     WebP
Logo with transparency                   PNG or WebP

magick photo.jpg -resize 1200x photo-1200.jpg

magick photo.jpg -resize "1200x630^" -gravity center -extent 1200x630 share.jpg

Common mistakes to avoid

Frequently asked questions