Surviving the upload form
Admission portals, job applications and government forms are the most demanding customers in image resizing: they specify exact pixels AND a file size cap, sometimes both. The workflow that works: set the exact required pixels first (Pad is your friend when the required shape differs from your photo: a border beats a rejection), then choose JPG and walk the quality slider down from 85 until the file sits under the limit. A 413×531 passport photo at quality 80 usually lands around 40–80 KB, comfortably under the typical 100–200 KB caps.
Two mistakes get applications sent back. Stretching a photo to hit exact pixels distorts faces, and reviewers notice. And screenshotting your photo to make it smaller produces a blurry, low-quality file that fails the 'clear and legible' requirement. Resize the original photo properly (one pass, correct pixels, honest quality) and you'll never hear from the portal's error messages again.
When to resize and when not to bother
Resize when something downstream demands it: an upload form with pixel or KB rules, a website where a 4000-pixel hero image is slowing the page, or a social platform that will crop your photo badly if you don't do it first. Those are the cases where the right size is the difference between success and an error message.
Don't bother when nothing will see the difference. Instagram scales everything you upload anyway, so resizing a photo to exactly 1080×1080 saves the platform a tiny bit of work and you nothing, though the preset is still useful if you want to frame the crop yourself rather than letting Instagram's uploader choose it. And never resize an image you're going to edit further: do the editing on the full-size original first, then resize once at the end. Every resize is a one-way trip.
How to Use Image Resizer
- 1Upload your images by clicking the drop zone, dragging files onto it, or pasting with Ctrl+V. Add one or as many as you like, up to 25 MB each; every image gets the same settings.
- 2Choose how to resize: type exact pixels (the aspect-ratio lock keeps your photo's shape), enter a percentage, or pick a preset: Instagram post, Story/Reel/TikTok, YouTube thumbnail, WhatsApp profile photo, a 35×45 mm passport photo, and more.
- 3When the new shape differs from your photo, pick a fit: Fit inside keeps the whole picture, Pad reaches the exact size with a fill colour, Fill & crop trims the edges, or Stretch forces the size (and distorts the photo).
- 4With 'Fill & crop', pick which part of each picture to keep on the 3 × 3 grid: the top for portraits so heads aren't cut off, or a side for a subject that isn't centred.
- 5Choose the output format: Original keeps each image's own format (a transparent PNG stays a PNG), or pick JPG, PNG, WebP or AVIF (where your browser can save it) for all of them, and set the quality. Set the file names with a pattern such as {name}-{w}x{h} or holiday-{n}.
- 6Tick 'Don't enlarge images that are already smaller' if some of your images are already under the target size. Then click 'Resize', check the result, and download: one image on its own, or several as a ZIP or one by one from the list. The output line shows the exact size you'll get before you click, and changing any setting clears the previous result, so a download always matches what you see.
Frequently Asked Questions
What's the difference between Fit inside, Pad, Fill & crop and Stretch?
Fit inside keeps the whole picture and its shape, so one side may end up smaller than you asked. Pad gives the exact size by adding a border in the colour you choose (or transparency for PNG/WebP). Fill & crop gives the exact size by trimming the overflow, centred. Stretch forces the exact size and distorts the picture.
Which presets are included?
Instagram post (1080×1080) and portrait (1080×1350), Story/Reel/TikTok (1080×1920), YouTube thumbnail (1280×720), Facebook cover (820×312), X header (1500×500), LinkedIn banner (1584×396), WhatsApp/profile photo (500×500), passport photo 35×45 mm at 300 dpi (413×531), Full HD, 4K and a 300×300 thumbnail.
Can I make an image larger than the original?
Yes, but enlarging can't add detail, so the result looks softer: the tool warns you when the output is bigger than the original. Tick 'Don't enlarge images that are already smaller' to leave those images at their own size instead, which is what you want when resizing a mixed batch down to a maximum. Very large outputs are capped at the biggest size browsers can draw.
Can I choose which part of the photo is kept when it's cropped?
Yes. With 'Fill & crop', a 3 × 3 grid sets the part to keep: top, middle or bottom, left, centre or right. The crop is still the exact size you asked for; only its position changes.
Can it save AVIF, and rename the files?
AVIF is offered when your browser can encode it (current Chrome, Edge and Firefox can); it usually makes the smallest files. File names come from a pattern: {name} is the original name, {w} and {h} the new size and {n} the image's number in the batch, so 'trip-{n}' gives trip-1, trip-2 and so on.
How does the aspect-ratio lock work?
With the lock on, changing the width recalculates the height to keep the original proportions, and vice versa, so the picture isn't distorted.
Can I resize many images at once?
Yes. Drop in as many as you like; they all get the same settings. With pixels or a preset and 'Fit inside', the width and height work as maximums and each image keeps its own shape; a percentage scales each image by its own size. Download them all as a ZIP or one at a time. Each image can be up to 25 MB, and everything happens in your browser, so nothing is uploaded.
Why does my resized photo look blurry?
Almost always one of two things: you made it larger than the original (enlarging can't invent detail, so edges go soft), or the quality slider is set too low. The fix is the same either way: start from the original file and don't push past its size. If the blur appeared after shrinking a very large photo, that's unusual; the tool downscales in steps precisely to avoid that.
An upload form says 'max 100 KB'. Will resizing fix that?
Usually, yes, in combination with the quality slider. Resize to the form's required pixels first: a 413×531 passport photo is only about 220,000 pixels, which doesn't need many kilobytes. Then set JPG quality around 75–85; that lands most passport and document photos well under 100 KB. If it's still over, lower the quality a notch rather than shrinking the pixels again. Never use Stretch to hit a required size: a distorted passport photo can get your application rejected.
What size is good for emailing photos?
1600 pixels on the long side at JPG quality 80. That's big enough to look great on any screen and small enough to sit around a few hundred kilobytes per photo, so ten of them won't clog anyone's inbox. Full 4000-pixel originals are for printing, not emailing.
About Image Resizer
Your phone just took a gorgeous 4 MB photo, and the admission portal just rejected it with 'file too large'. Or LinkedIn wants a banner at exactly 1584×396 and your picture is whatever your camera felt like. Resizing is one of those tiny jobs that blocks the actual thing you were doing: the application, the upload, the post. The Image Resizer changes an image's dimensions to exact pixels, a percentage, or a ready-made size for social media, documents and the web.
Processing runs in your browser on an HTML canvas, downscaling in steps for smooth, sharp results rather than the jagged edges of a single big jump. Photos are decoded upright, so phone pictures keep their correct orientation. The four fit options cover every case where the target shape differs from your photo: keep everything (Fit inside), reach an exact size with a border (Pad), fill the frame and trim the edges (Fill & crop), or force the size (Stretch). The output line shows the exact size you will get before you click.
The presets do the arithmetic you shouldn't have to. A passport photo for an online application is 35×45 mm at 300 dpi, which is 413×531 pixels. Nobody should have to look that up twice. A YouTube thumbnail is 1280×720, and the WhatsApp / profile photo preset is 500×500. Picking WebP output resizes and converts in one step, saving bandwidth for websites. And because changing any setting clears the previous result, the file you download always matches the preview you're looking at.