How to Resize an Image Without Losing Quality: A Simple Guide

What does resizing do to an image?

Resizing changes the width and the height of a picture in pixels. It does not change what the picture shows. Do not confuse it with compression, which reduces the file size by storing the pixels more efficiently. You can use both, and the best order is to resize first and compress afterwards.

Making a picture smaller is safe. The tool only has to combine pixels, and the result stays sharp. Making a picture bigger is the risky direction, because the tool has to invent pixels that were never there.

How resizing works

A digital picture is a grid of tiny colored squares called pixels. A photo that is 4000 pixels wide and 3000 pixels tall contains 12 million of them, which is 12 megapixels. If you resize it to 1200 pixels wide, it becomes 1200 by 900 pixels, which is about 1 million pixels. That is roughly eleven times fewer, and the file becomes much smaller too.

On a normal screen, a 1200 pixel wide picture looks the same as the 4000 pixel one, because the screen cannot show the extra detail anyway.

Step-by-step: resizing your images

• Step 1: Add your images. Drag your pictures into the box or click Choose images. You can add up to 20 images at a time, up to 25 MB each.
• Step 2: Pick a method. Choose By size, By percentage or Social presets.
• Step 3: Set the size. Enter the width, move the percentage slider or choose a preset. The result updates automatically.
• Step 4: Choose the output. Pick the output format and the quality. For photos, JPG or WebP at about 80 percent is a good balance.
• Step 5: Download. Download each image, or click Download all to save everything at once.

Three ways to resize, with examples

• By size. Enter a width of 1200 for a 4000 by 3000 photo, with Keep aspect ratio on, and the height becomes 900 by itself.
• By percentage. Choose 50 percent and the same 4000 by 3000 photo becomes 2000 by 1500.
• Social presets. Pick a ready-made size, such as 1080 by 1080 for an Instagram post, 1280 by 720 for a YouTube thumbnail or 1200 by 630 for a link preview. The picture is scaled and cropped to fit.
• Video-shaped pictures. A 1920 by 1080 picture becomes 1280 by 720 when you keep the aspect ratio, because both have the same 16 to 9 shape.

Why you should keep the aspect ratio

The aspect ratio is the relationship between the width and the height. A photo of 4000 by 3000 pixels has a ratio of 4 to 3, and a video-shaped picture of 1920 by 1080 has a ratio of 16 to 9. If you change only one side and leave the other, the picture is stretched and faces and logos look wrong.

Leave Keep aspect ratio turned on and enter one side only. The tool calculates the other side for you.

Making an image smaller or bigger

Shrinking keeps a picture sharp, so it is the best way to resize. Enlarging makes it softer, because the new pixels are guesses based on the old ones. If you must make a picture bigger, do it once, by a small amount, and start from the biggest original you have.

If you need a bigger picture for printing or a banner, use the Upscale Image tool, which enlarges in steps and adds a little sharpening. It cannot create real detail, so a larger original always gives a better result.

Which size should you use?

• Pictures in a blog post or on a web page. A width of 800 to 1200 pixels is enough for most layouts.
• Email attachments. A width of about 1600 pixels keeps the picture sharp on most screens and the file small.
• Thumbnails and small previews. A width of 300 to 600 pixels is usually enough.
• Link previews. 1200 by 630 pixels is the common size for the picture that appears when your page is shared.
• Printing. Keep more pixels for print. Resize only if the print shop gives you a size to use.

Resize first, then compress

Resizing lowers the number of pixels, and compression lowers the size of the file. A very large photo that is only compressed is still too big for the screen, and a resized photo that is not compressed can still be heavier than needed. For the best result, resize to the size you need, save it as JPG or WebP at about 80 percent quality, and then use the Image Compressor if you want the file even smaller.

Tips to avoid losing quality

• Start from the original. Resize from your biggest copy, not from a picture that was already resized or compressed.
• Resize once. Every resize and every save loses a little detail, so do it in one step.
• Choose the right format. Use JPG or WebP for photos, and PNG or WebP for logos, screenshots and pictures with a transparent background.
• Check the crop on presets. Presets crop the picture to fit an exact shape, so keep the important part near the center.
• Keep your originals. Resizing creates new files. Keep the originals in case you need another size later.

Common problems and fixes

• The picture looks stretched. Keep aspect ratio was off. Turn it on and enter only one side.
• The picture looks blurry. It was probably made bigger than the original. Use a larger original or keep the picture at its real size.
• The file is still large. Lower the quality a little, choose WebP or JPG, or use the Image Compressor.
• A preset cut off part of my photo. Presets fit the picture to an exact shape by cropping. Use By size if you want to keep the whole picture.

Resize your images now

Use our free image resizer to change the size of your pictures in seconds. Everything happens in your browser, so your images are never uploaded. It is free, adds no watermark and needs no signup.

Frequently asked questions