What is JPEG, and why can it get so much smaller?
JPEG (also written JPG) is the most common photo format in the world. It was designed for photographs: it divides the picture into small blocks and keeps the information the eye notices most, such as brightness, while simplifying fine colour detail.
The amount of simplification is set by a “quality” value. Cameras and phones often save photos at a very high quality, which produces big files for very little visible benefit. Re-saving the same photo at a slightly lower quality, with a better encoder, often cuts the size by half or more.
That is exactly what Plume does. It uses MozJPEG, an open-source encoder created by Mozilla to produce smaller JPG files that any device can open. The result is a normal JPG: it works in every browser, phone, printer and office program.
How to reduce JPG size without visible loss
A few simple rules give the best results:
- Start with Balanced. For most photos, this setting gives a much smaller file that looks the same on a screen.
- Check the size shown. Plume displays the size before and after for every file. If you need even less, move the slider down a little.
- Resize when the photo is huge. A 4000-pixel-wide photo shown on a website or in an e-mail rarely needs more than 1600 to 2000 pixels. Setting a maximum width saves far more than lowering the quality.
- Work from the original. Each JPG save loses a little detail. Compress the original file once rather than re-compressing a copy several times.
For printing, keep High quality and the full resolution. For sharing, Balanced is almost always enough.
Compress a JPG for e-mail, WhatsApp or an online form
Phone photos often weigh 3 to 6 MB each. That is fine on your phone, but quickly becomes a problem elsewhere:
- E-mail: Gmail limits attachments to 25 MB and Outlook to 20 MB. A handful of photos can fill that.
- Messaging apps like WhatsApp compress photos on their own, sometimes harshly. Compressing yourself first gives you control over the result.
- Administrative portals, job sites and rental platforms often accept only files under 2 to 5 MB. With the Smallest preset and a sensible maximum width, a photo of a document usually fits easily.
If your photo is in another format, such as a screenshot in PNG, you can turn it into a JPG with PNG to JPG.
Private by design: nothing leaves your computer
Plume compresses your JPGs directly in your browser. Unlike most online tools that upload your files, nothing is sent to a server. You can check it yourself: after the page has loaded, disconnect from the internet and the tool keeps working.
Plume also removes EXIF metadata by default. This hidden data can include the date, your phone model and the GPS location of the photo. Removing it is a good reflex before posting a picture online or sending it to someone you do not know. The orientation is preserved, so portrait photos stay upright.
Batch compress JPG files for free
Select a whole folder of holiday photos or product pictures and drop them in. Plume processes them all with the same settings and lets you download them as one ZIP file. There is no account, no watermark and no daily limit.
The speed depends on your device. A recent computer handles hundreds of photos comfortably; on a phone, smaller batches work best.
Need other formats too? The general image compressor also handles PNG, WebP, AVIF and HEIC, and JPG to WebP can make web images even lighter.