How to use this image compressor
- Drag your images onto the dropzone, or press Browse files to select them.
- Set the compression quality. Start at 80% and adjust once you have seen the results.
- Leave the format on Keep original, or switch to JPG or WEBP for bigger savings.
- Press Compress images and wait for the batch to finish.
- Check the saving shown against each file, then download individually or as a ZIP.
What this compressor does
- Works on JPG, PNG and WEBP files in the same batch without separate tools.
- Reports the exact saving per file and the total kilobytes recovered.
- Lets you switch format mid-compression, which often saves more than the quality slider alone.
- Keeps the original pixel dimensions, so nothing is silently downscaled.
- Strips the EXIF block as a side effect, removing camera and location data.
- Handles twenty files per run with no daily limit and no watermark.
What compression actually changes
An image compressor does not make a picture smaller on screen. It reduces the number of bytes needed to describe the same grid of pixels, which is why a 4 MB photograph can become 400 KB while still filling the same space in your layout. The saving comes from throwing away information the eye is poor at noticing, subtle colour variation in smooth areas, fine detail in busy textures, and precision that no display can reproduce anyway.
How much you can throw away before it shows depends entirely on the picture. A photograph of a forest hides an enormous amount of loss because the detail is already chaotic. A screenshot of a spreadsheet exposes every artefact, because flat colour and sharp text are exactly what compression handles worst.
Where a smaller file makes a real difference
- Page speed: images are usually the heaviest thing on a web page and the main cause of a slow largest contentful paint.
- Email: most servers reject attachments over 10 or 25 MB, and a compressed set of photos slips under easily.
- Storage: a phone backup or client archive shrinks dramatically with no visible change.
- Uploads: marketplace listings, job portals and CMS forms all impose per-image ceilings.
- Data cost: visitors on a metered mobile connection pay for every kilobyte you send them.
Reading the quality slider properly
The number is not a percentage of quality retained. It is an encoder setting, and the relationship to visible quality is not linear. Between 100 and 90 the file shrinks a great deal while almost nothing visible changes. Between 90 and 75 the savings continue and only close inspection reveals softening. Below about 65 the classic symptoms arrive: blocky patches in skies and gradients, and a faint halo around high-contrast edges.
Because the results list shows the size change for every file, the practical method is empirical. Run a batch at 80, look at the numbers, open one result, and adjust only if you need to. Most people find they were compressing far too little rather than too much.
Changing format is often the bigger win
The quality slider is only one lever. If your source is a PNG photograph, no quality setting will help much, because PNG is lossless by design, the format itself is the problem. Switching that file to JPG or WEBP typically saves eighty to ninety-five per cent, far more than any adjustment within PNG.
WEBP is the most efficient of the three and is supported by every current browser, so it is the right choice for web use. JPG is the safer choice when the file is going somewhere unpredictable, such as an email attachment or an older upload form. For a dedicated route in either direction, the PNG to JPG converter and the JPG compressor give you the same engine with fewer decisions to make.
When resizing beats compressing
If a photograph is 6000 pixels wide and will be displayed at 800, compression is solving the wrong problem. Reducing the dimensions cuts the pixel count quadratically, halving the width and height leaves a quarter of the data before any compression is applied at all. Run the picture through the image resizer first, then compress the result, and the combined saving is far greater than either step alone.
Everything here happens inside your browser. The files are decoded, redrawn and re-encoded in local memory, so no copy is uploaded and nothing is retained on a server. That also means the speed of a batch depends on your own hardware rather than a shared queue.