Compress images by changing the output format, lowering quality or reducing their dimensions. Add your pictures above to see the actual result in bytes, including when a file gets larger. This page starts with WebP at 80% quality and keeps the original pixel size. You can choose JPG for an upload form that requires it, or PNG when preserving decoded pixels matters more than reducing file size.
Three controls that affect file size
Format decides how the picture is stored. Photos often compress well as JPG or WebP. Logos, diagrams and screenshots can be efficient as PNG because they have large areas of a single color and sharp edges. There is no single format that makes every picture smallest.
Quality trades detail for fewer bytes in JPG and WebP. The manual slider runs from 50 to 100%. The percentage is an encoder setting, not a claim that 80% of the original detail remains or that the file will be 80% of its previous size. Inspect the result, particularly around small text, edges and smooth gradients.
Dimensions control how many pixels must be stored. A photo intended for a small web panel may not need its original camera resolution. Under Resize and file size, choose a width, height, bounding box or percentage. The image resizer explains those modes with worked examples. Proportions are preserved, and smaller originals are only enlarged if you allow it.
Using a file-size target
Enter the maximum number of KB you would like each image to use. Here, 1 KB means 1,000 bytes, so a 100 KB target means 100,000 bytes. With JPG or WebP selected, the compressor starts at your chosen quality, then tries lower values down to 10% if needed. It retains a tested result under the target when it finds one. The result row includes the quality actually used.
Some combinations are impossible without reducing dimensions. A large, detailed photograph may still be above a small limit at the lowest quality. That image remains downloadable, but both its row and the batch status identify the missed target. It is not silently cropped or shrunk to claim success. Choose a smaller width or a different format, then check again.
Leave the target blank to use exactly the quality selected on the slider. A file already under the target at that quality needs no further quality reduction. For a form with a strict upload limit, leave a little room below its stated maximum, since services do not always use the same definition of KB and may apply other checks.
Preview before you download
The thumbnail helps identify each image; Preview opens the saved output at a useful viewing size. Turn on Actual pixels to inspect it without scaling it down to fit the window. Check small lettering, textured fabric, hair and the edges of a subject. A small file is not useful if the important detail becomes unreadable.
The size comparison uses the original file you selected and the actual new file. It can show a saving, a larger result or the same size. No estimated percentage is substituted for the download's measured size. If you dislike the result, change the settings: every attempt starts from your selected original, not from the last compressed output.
Transparency and PNG files
WebP is the starting format because it combines adjustable compression with transparency. With JPG, transparent areas must become a solid color; choose white or black to match where the image will be used. The PNG to JPG guide shows when this conversion is useful and when to keep PNG instead.
PNG has no lossy quality setting in this tool and does not support the KB target. Re-encoding an unchanged PNG might make it larger. For a smaller transparent file, try WebP or reduce the dimensions. If the receiving app rejects WebP, the WebP to PNG converter produces a compatible PNG while retaining transparency.
Working through a batch
All settings apply to the full list, but each image is encoded separately. Different pictures may therefore use different quality levels to meet the same target. Processing is serial to keep memory use controlled. You can remove a file while the others finish, download ready results individually, or wait for the ZIP button.
The ZIP packages the output files; it does not give already compressed images another dramatic size reduction. Keep the source files for future edits and metadata. These outputs omit the originals' camera details, capture date and GPS information, and animated inputs become still pictures. All image processing takes place in your browser, with no signup or watermark.
Frequently asked questions
Can I compress an image to 100 KB?
Enter 100 under Aim for at most (KB), with JPG or WebP selected. The tool tries lower quality at your chosen dimensions and checks the actual encoded bytes. If it cannot get below 100,000 bytes, the row says it is above the target. Resize the image or change the format and try again.
Is image compression lossless here?
JPG and WebP quality settings are not a lossless guarantee, even at 100%. PNG output is lossless for the decoded pixels, but it has no quality or file-size-target control. Resizing any format removes or interpolates pixel information.
Why did my file get larger?
The original may already use efficient compression, or its format may suit the picture better. A screenshot can be smaller as PNG than JPG, for example. The result shows a size increase honestly; you can keep the original or try a different setting.
Will compressing remove a transparent background?
WebP and PNG keep transparent areas. JPG replaces them with your selected white or black background. The converter does not automatically remove an opaque background.
Does the target apply to each image or the whole ZIP?
It applies to each JPG or WebP image separately. A ZIP contains the finished files, and its total size can be much larger than the per-image target.
Are the pictures uploaded or stored online?
No. The browser reads, resizes and encodes your files locally. The site never receives the images, their file names or the size target you enter.