Image Compressor

How to use the Image Compressor

1. Drop up to 20 JPG, PNG or WebP images onto the upload area, or click it to choose files. Each file is checked by its contents, not just its name.
2. Set the JPG and WebP quality. The default is 80, and lower values give smaller files. PNG files ignore this setting because they are optimized without losing any detail.
3. Select Compress Images. Images are processed one at a time with a progress count, and you can cancel at any time.
4. Check the size change shown for each file, then download the images one by one or select Download All (.zip).

Supported formats: JPG, JPEG, PNG and WebP input, up to 20 files per batch and 50 MB each. The output keeps each file's format; animated images and HEIC are not accepted.

What image compression does

An image file is a description of millions of pixels. Compression stores that description in fewer bytes, either by finding patterns it can write more compactly or by deliberately dropping detail the eye is unlikely to miss. The result is a file that downloads faster, fits an upload limit and takes less storage, while the picture stays the same size.

How much a file shrinks depends mostly on what is in it. Photographs full of texture and noise leave less room than flat graphics, and an image that has already been compressed once has less left to give.

Compress JPG, PNG and WebP

The three formats are compressed in three different ways, which is why the tool does not give them one shared setting.

To compress a JPG or to compress a WebP, the tool re-encodes the picture at the quality you choose, which is why those two have a quality slider. To compress a PNG, it rewrites the same pixels more efficiently, which is why a PNG has no quality setting at all.

Lossy vs lossless compression

Lossy compression permanently discards some detail in exchange for a much smaller file. JPG and WebP use it here. The loss cannot be undone, and compressing the same file again discards more, so keep the original when you may need the best copy later.

Lossless compression stores exactly the same picture in fewer bytes, the way a ZIP file does for documents. PNG is lossless by design, and this tool only ever optimizes PNG losslessly. The savings are usually smaller than lossy compression gives, but nothing is lost.

JPEG quality explained

The quality slider runs from 10 to 100 with a default of 80. It controls how aggressively a JPG or WebP is compressed. It is not a percentage of the original size, and it is not a promise of a particular file size: two photos at the same setting can end up very different sizes.

How PNG lossless optimization works

A PNG stores its pixels with a filter and a general-purpose compressor. Optimizing it means trying other filter choices and a stronger compression pass, and using a smaller way to store the colors when the image allows it, for example a palette for an image with few colors. The picture that comes out is identical, pixel for pixel, including the transparency and the colors hidden under fully transparent pixels.

This is slower than re-encoding a JPG, because the optimizer tries many combinations. A large PNG can take a minute or more, and the tool shows a note when it expects that. It runs in a background worker, so the page stays usable, and you can cancel at any time. The tool uses one fixed optimization level, because a slower setting saved well under one percent more in testing for several times the wait.

WebP compression

WebP is a modern format that usually makes a smaller file than JPG at similar quality and supports transparency. This tool re-encodes WebP images with your browser's own WebP encoder at the chosen quality and keeps their alpha channel. If a browser cannot produce a real WebP image, the tool reports an error instead of saving another format under a .webp name.

Two cases can make a WebP larger. A lossless WebP is re-encoded as a lossy one, which can be bigger for small or flat images, and the highest quality settings can switch some browsers to lossless encoding, which is much bigger than a normal lossy file. For smaller WebP files, keep the quality below 100.

Compression vs resizing

Compression keeps every pixel position and changes how the file stores them. Resizing changes how many pixels there are. A 4032 × 3024 photo compressed here is still 4032 × 3024, which is why this tool has no width, height or scale setting.

If a destination demands specific dimensions, use the Image Resizer. If the dimensions are already right and the file is too big, compress it here. For the two together, resize first and compress the result.

4032 × 3024 JPG at quality 80

A JPG that is still 4032 × 3024 and the right way up, usually much smaller

1200 × 800 PNG

A PNG that is still 1200 × 800 with identical pixels and the same transparency, never larger than the original

Compression vs format conversion

This tool never changes a file's format, even when another format would be smaller. A PNG is not turned into a WebP and a WebP is not turned into a JPG behind your back. If you want a different format, use the Image Converter, which changes the format and keeps the pixel dimensions.

The JPEG Compressor is a separate, specialized tool: it takes one image at a time, always outputs a JPEG even from a PNG or WebP source, and offers scaling and a target file size. Use it for that workflow. Use this tool for batches that must keep their formats and dimensions.

Why an optimized file can sometimes be larger

Re-encoding a JPG or WebP always writes a new file at the quality you picked. If the original was already compressed harder than that, for example a web image saved at a quality below your setting, the new file stores more detail than the old one and can be bigger. The tool reports that honestly, for example 12% larger, and suggests a lower quality, instead of calling it a saving.

A PNG cannot get larger: the tool compares the optimized file with the original (with the same metadata removed) and keeps the smaller one.

Image metadata and privacy

Photos can carry EXIF details such as the camera model, the capture time and the GPS location. JPG and WebP files made here are encoded from decoded pixels by your browser, which does not copy that information, so they are safe to share without leaking where a picture was taken. PNG files are rewritten without text notes, modification times and EXIF data.

What is kept is whatever changes how the picture looks: for a PNG that means transparency, color profile information, gamma, background color and print density, and a rotation stored in a PNG's EXIF is kept as a new orientation-only record, with every other EXIF field removed. A JPG's rotation flag is applied to the pixels instead of being kept, so the result is upright without depending on any tag. Color profiles can be rewritten or removed when a browser re-encodes JPG and WebP, so this tool is not for professional color-managed workflows.

Batch compression

Images are compressed strictly one at a time, with a Compressing 3 of 8 count, which keeps memory use predictable and makes Cancel immediate. One damaged file does not stop the rest: the summary reports how many were compressed and how many failed.

Each finished image has its own download button. A batch with more than one finished image can also be downloaded as compressed-images.zip, built only from the results on screen when you select it. Output names add -compressed to the original name and keep its format, and duplicates become photo-compressed.jpg, photo-compressed-2.jpg and so on, so nothing in the ZIP overwrites anything else.

Choosing the right setting

• Photos for a website or email: start at the default of 80 and check the result. Go lower only if you still need a smaller file.
• Images you will keep editing: keep the original, and use a quality of 90 or more if you must re-encode.
• Logos, screenshots and graphics with sharp edges or transparency: PNG, which is optimized without any loss. For flat graphics this is often a large saving.
• A file that came out larger: lower the quality, or keep the original, since it was already well compressed.
• A file that is still too big after compressing: resize it with the Image Resizer, or turn several into one document with Image to PDF.

Things worth knowing

• JPG and WebP compression is lossy. Detail that is discarded cannot be recovered, and a result can be larger than the original if the original was already compressed harder than your quality setting.
• Only JPG, PNG and WebP are accepted. HEIC photos need the HEIC to JPG Converter first; GIF, AVIF, SVG, BMP and TIFF files are not supported.
• Animated WebP and animated PNG files are refused, because compressing them here would keep only the first frame.
• Pixel dimensions are preserved, not changed. This tool does not resize, crop or rotate; use the Image Resizer for a different size.
• The format is preserved too. Use the Image Converter to change it.
• Up to 20 images per batch, 50 MB per image and about 50 megapixels per image (a 48 megapixel phone photo fits). Larger files are refused with a message.
• Metadata is removed from JPG and WebP files, and color profiles can be rewritten or removed. Do not use this for professional color-managed work.
• Very large images can still exceed what your browser's memory allows, particularly on phones, and some mobile browsers limit the size of the canvas used to re-encode JPG and WebP.
• Lossless PNG optimization of a large image can take a minute or more.

Frequently asked questions

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