Free Online Image Resizer

Resize Images Online

The free online image resizer sets a JPG, PNG or WebP to an exact width and height in pixels or scales it by a percentage, with the aspect ratio locked so nothing stretches. Because it runs in the browser, the images are never uploaded.

Image sizing work by OnlinePCApps since 2013

No upload Lock ratio Social presets Free
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Free, always
Why resize images online

Three Reasons to Resize an Image

A photo straight from a phone or camera is often 4000 pixels wide or more, far larger than the slot it has to fit. The free online image resizer sets the exact width and height a place asks for, with the proportions kept intact.

Fit a Platform's Exact Size

A profile photo wants 400 by 400, a banner wants a fixed width and a marketplace rejects anything off its dimensions. Typing the required pixels produces a picture that fits the slot without cropping surprises.

An image at the required dimensions.

Serve Images at Display Size

A 4000 pixel photo shown in an 800 pixel column forces the browser to download and shrink it on every visit. Resizing to the width the layout actually uses cuts wasted bandwidth and helps the page paint sooner.

Pixels matched to the layout.

Meet a Print or Document Spec

A passport photo, a visa form or a print order lists exact pixels at a set DPI. Entering the dimensions and the resolution produces a file that matches the specification the office prints from.

A file that meets the spec.
How it works

Resize an Image Online in Three Steps

1

Add the Images

Drop the pictures onto the panel, or choose them from a folder. One photo works, and so does a whole set loaded together as JPG, PNG or WebP.

4000px Width x Height 800 x 600 lock ratio
2

Set the Dimensions

Type an exact width and height in pixels, drag the percentage slider or pick a ready preset. With the ratio lock on, one value fills in the other so nothing stretches.

photo · 800px
3

Download the Result

Keep the resized picture, or pull a full batch down as a ZIP. Every original is left untouched, ready to run again at a different width whenever needed.

Exact pixels Width and height
Ratio locked No stretching
One or a batch Download or ZIP
Need it faster?

Resize Hundreds of Images at Once

A handful of pictures resize in a moment right here. For a folder of hundreds, or a whole photo library headed for the web, the desktop app reads from disk and sets the entire set to one width, one percentage or one preset in a single pass.

Get Desktop Version Free trial · Windows 7 to 11
What the free tool does

What the Image Resizer Does

To resize an image is to change its width and height in pixels. The tool does that on the device.

Resize by Exact Pixels or Units

Type a width and a height in pixels, or switch to centimeters, millimeters or inches with a DPI for a print job. With the ratio lock on, entering one value fills in the other, so a 4000 by 3000 photo becomes 800 by 600 with no guesswork and no stretching.

Scale by Percentage

A percentage from 1 to 400 scales the whole picture up or down while the proportions hold. Half size is 50 percent, double is 200 and the read-out shows the pixel dimensions the percentage works out to.

Fit a Ratio or Preset

A preset ratio such as 1:1, 4:3, 4:5, 16:9 or 9:16 sets the shape in one tap, with 4:5 now the preferred portrait for a feed. Ready presets for Instagram, Facebook, Twitter, Pinterest and YouTube, plus screen widths of 1920, 768 and 320, apply the exact pixels each place expects.

Choose How It Fits

When the new shape differs from the old, the fit mode decides the look. Crop trims the overflow, pad adds a solid or blurred bar to keep the whole frame and stretch forces the exact box when a little distortion is acceptable.

Resize an image, change image size and resize a photo all point to one action here. Whether the search reads resize JPG, resize PNG or photo resizer, it lands on this tool and each source stays exactly as it arrived.

Reference

What Resizes Cleanly and What to Watch

Resizing changes the pixel count of a picture. These points decide how sharp the result looks and when to watch out.

The caseResultWhat happens and why
Downscalingstays sharpRemoving pixels the display no longer needs keeps the picture clean.
UpscalingsoftensEnlarging invents no detail, so edges blur past roughly double size.
Ratio lockedno distortionOne value fills in the other, so the picture never stretches.
Ratio changedcrop or padCrop trims the overflow, pad adds bars, stretch forces the box.
Percentage scaleproportionalFrom 1 to 400 percent the shape holds while the pixels change.
Units and DPIpx, cm, inPixels suit a screen, while centimeters or inches with a DPI suit print.
Social presetsexact pixelsA platform size such as 1080 by 1080 or 1080 by 1350 is applied in one tap.
Smoothinghigh qualityA high-quality bicubic or Lanczos-class filter on downscale avoids moire and aliasing.
TransparencykeptA PNG or WebP keeps its clear background through the resize.
Where it runson the deviceEvery picture is processed in the browser, so nothing is uploaded.

The Same Picture at New Dimensions

Resizing is a two-step bitmap operation: the source file is decoded to a bitmap, then drawn to a new canvas at the target width and height, where a resampling filter interpolates between the source pixels. The direction matters. Downscaling is the well-behaved case, because a properly band-limited filter drops the detail that cannot survive at the lower pixel count, so the result stays clean and free of moire and aliasing. Upscaling is the harder case, since enlarging cannot invent detail that was never captured, so the output softens and a stretch beyond roughly double size shows blur. Two honest points guide the work. The aspect ratio lock keeps a picture from distorting, because one value fills in the other and the proportions never change. And the quality of a shrink depends on the resampling filter: nearest-neighbor is blocky, bilinear is soft, while a browser sets its high smoothing level to a bicubic or Lanczos-class filter through the Canvas imageSmoothingQuality property, the class of resampling that Photoshop and GIMP reach for. Resizing to display size is also the step to do before compressing, not after. The references below define the formats and the browser drawing model the resizer uses.

Honest comparison

In the Browser vs a Hosted Resizer

Both resize an image. The trade is real, and a photo is often a personal one.

Point of comparison This tool Resized in the browser On the device Hosted resizer Uploaded and resized on a server
Where the photos go Never leave the device Uploaded to a server
Price and caps Free with no file cap A free plan is usually limited
Camera RAW files Common web formats here RAW opens on a server or desktop
Hundreds of images A set at a time in the browser A big batch runs on their machines
A saved dimension preset Entered fresh in the tab each visit A desktop app remembers it

Those last three rows favour a desktop or hosted route, because camera RAW, a run into the many hundreds and a remembered preset each ask for more than a single tab can offer. For everyday photos the top two rows decide it: the pictures stay put and the work carries no charge or cap.

Why no upload

The Photos Never Leave the Device

Every picture is repainted at its target dimensions on a canvas inside the tab itself. That keeps the work local to whichever machine opened the page, with no file handed to a server for processing.

Pictures are often private: a screenshot, an ID card, a family shot none of which belong on someone else's server. Plenty of hosted resizers take a copy and pledge to erase it later. Doing the work on the device skips that transfer altogether.

1. Open developer tools and select Network
2. Empty the log, then leave it recording
3. Resize a few images with the panel above
Nothing uploads. The files were resized on the page itself.
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Alternatives

Other Ways to Resize an Image

Each of these changes a picture's dimensions. They differ in effort, in cost and in where the file goes.

macOS Preview

Tools then Adjust Size sets a new width and height in pixels.
It works on the Mac with no download.
It is a Mac feature and offers no social presets.

Upload Resizers

Many sites resize an image after uploading it to a server.
They often offer presets and batch in one place.
The photo leaves the device and free tiers are often capped.

Microsoft Paint

The Resize dialog sets pixels or a percentage on Windows.
It ships with Windows and needs no download.
It is Windows only and has no ratio presets or batch.

ImageMagick

A terminal utility that scales and batches a folder in one command.
Fully offline with control over every setting.
Comfort with a command line and its flags is a must.

Preview, Paint and ImageMagick all keep the file on the computer, but one is Mac only, one is Windows only and one lives at a terminal. This page stays every bit as local while folding in social presets and batch resizing, with nothing to install first.

Before resizing

Three Things to Know Before Resizing

A moment of background decides how to approach it.

Keep the Original

A downscaled file has thrown away pixels, and enlarging it back does not restore them. Resizing a copy and keeping the full-resolution master means there is always a clean source to export from at any size.

Downscale, Do Not Upscale

Shrinking a large photo is clean, because the filter drops only the detail the smaller size cannot hold. Enlarging a small one invents no detail, so past roughly double size the edges turn soft and blurred.

Resize First, Then Compress

Order matters when a file needs both. Setting the dimensions first and compressing after keeps the result clean, while compressing first and enlarging later amplifies the artifacts that were already there.

The desktop edition

When Hundreds of Images Need Resizing

A handful of pictures works from memory inside the tab, which suits whatever is open at that moment. Point a folder of hundreds, or an entire library headed for a site, at the desktop edition instead: it pulls each file off disk and drives the whole set to one width or preset in a single run.

In a browser taba set at a time
On the desktopa whole folder in one pass
Whole Folders

Set it on a folder of pictures and each file is brought to the target width in one sweep, written next to the source.

Saved Presets

A preset holds a width, height, ratio and format, so a repeated job runs the same way each time in one click.

RAW and TIFF

Camera RAW straight off a DSLR and multi-page TIFF are opened and resized, file types a browser tab cannot decode by itself.

Common questions

Image Resizer Questions

It changes the width and height of a picture in pixels. Type exact dimensions, drag a percentage or pick a preset, so the image is redrawn to that size on the device, with the aspect ratio locked so it never stretches.
Add the image, turn the ratio lock on and type the width so the height fills in to match. Type both a width and a height together for a fixed box instead. A 4000 by 3000 photo becomes 800 by 600 the moment the numbers are set, and the preview shows the result before saving.
Yes. With the lock on, entering one dimension calculates the other from the original proportions, so the picture is never squashed or stretched. Turning the lock off allows a free width and height when a fixed box matters more than the shape.
Yes. A percentage from 1 to 400 scales the whole picture while the proportions hold, so 50 percent is half size and 200 percent is double. The read-out shows the pixel dimensions the percentage works out to.
Pick the platform preset and the exact pixels are applied in one tap, such as 1080 by 1080 for a square post or 1080 by 1920 for a story. Presets for Facebook, Twitter, Pinterest and YouTube cover the common post and thumbnail sizes.
Downscaling keeps the picture sharp, because the filter drops only the detail the smaller size cannot hold. Enlarging is where quality suffers, since no tool can invent detail that was never captured, so a big upscale looks soft.
Up to a point. A mild enlargement under about double size holds together, but beyond that the edges blur because upscaling interpolates between existing pixels rather than adding new detail. Starting from the highest resolution original gives the best result.
The fit mode decides. Crop trims the overflow to fill the new frame, pad adds a solid or blurred bar to keep the whole picture visible and stretch forces the exact box when a little distortion is acceptable.
The same way for both. Add the JPG or PNG, set a width and height or a percentage, then download in the same format or another. A JPG stays a photo format, while a PNG keeps any transparency through the resize.
It is, as long as the output stays PNG or WebP, since both carry an alpha channel through a resize. JPG has no such channel, so a see-through background becomes a flat colour once saved that way.
Yes. Load a batch and apply one width, one percentage or one preset across all of them, then download singly or as a ZIP. File names are preserved, so an entire folder finishes in one go.
No. Every picture is repainted at its new size through the browser Canvas API, so nothing leaves the computer. A hosted resizer typically takes a copy and clears it hours on, whereas the Network panel in developer tools stays blank here for the whole resize.
Resizing changes the pixel dimensions, the width and height. Compressing changes the file size in KB at the same dimensions. They pair well: resize a photo to its display size first, then compress, for the smallest sharp file.
Yes. Enter the exact pixels the office lists, and set the DPI when the form asks for a print resolution. A US passport photo is 2 by 2 inches, which is 600 by 600 pixels at 300 DPI, while India and much of the EU use 35 by 45 mm, about 413 by 531 pixels at 300 DPI. The picture is produced at those dimensions, ready for a document upload or a print order.
Yes. Switch the unit to centimeters, millimeters or inches and set a DPI. The tool works out the pixel dimensions from the physical size, so a 10 by 15 cm photo at 300 DPI comes to 1181 by 1772 pixels, the resolution a print shop expects.
Yes. One-tap widths cover common screens at 1920, 768 and 320 pixels, along with a 16:9 shape for a wallpaper or a video still and a 1280 by 720 size for a thumbnail. Each preset locks the matching ratio so the important part is not cropped away.
It does, inside any mobile browser with no app to add. Pull a shot from the camera roll, set the pixels or a preset and write the result back to the phone, useful for a quick social post or upload on the move.
No. What comes out holds the picture and nothing else. There is no house mark, no watermark, no stamp in the corner, so the file is ready to publish or share as is.
A static page is cheap to host, and since the free online resizing happens in the browser, no image is ever collected or stored. The desktop edition is what funds the work, built for large batches, remembered presets and camera RAW. Where many hosted resizers throttle a free account, this one places no such limit.

OnlinePCApps Media Group

Written and reviewed by Yara Haddad, who has worked on image scaling and browser graphics here since 2013

Last reviewed August 2026
13
Years on file formats
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Images uploaded
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Exact dimensions
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Watermarks

Good resizing is mostly about respecting the pixels a picture actually has. Downscaling is the friendly direction, because a shrink guided by a proper filter drops only the detail the smaller size cannot hold, so the result stays clean and sharp. Enlarging is the honest limit worth repeating, since no algorithm can invent detail that was never captured, so an upscale past roughly double size turns soft. The aspect ratio lock is the other thing that matters, because it fills one dimension from the other and keeps a picture from stretching. A quiet detail sits under all of it: a browser sets its high smoothing level to a bicubic or Lanczos-class filter through the Canvas, the same class of resampling desktop editors reach for. Since a photo is often a private thing, the whole job runs in the browser and sends nothing to a server.

Standards followed

JPEG · ISO/IEC 10918 PNG · W3C WebP · Google Canvas API · MDN
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Resize Images Online for Free

Free and online, with no sign-up and no upload. Set a picture to any width and height in the browser, all on the device.

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