Compress Images
Reduce image file size while maintaining visual clarity.
How it works
Select Images
Upload one or more images for compression.
Enter target size
Type the size you want per image in KB or MB, for example 200 KB.
Download
Download optimized images individually or as a ZIP.
About This Tool
Large image files slow down websites, fill up storage, and create friction when sharing. JustConvert's Image Compress tool reduces the file size of JPG, PNG, and WebP images using smart compression algorithms that maintain strong visual quality at significantly smaller sizes.
Batch compression lets you upload multiple images at once. Three quality presets — Maximum Compression, Recommended, and Minimal Compression — give you control over the size-vs-quality trade-off. All compressed images are available as individual downloads or a batch ZIP file.
- Supports JPG, PNG, and WebP images
- Batch compress multiple images at once
- Three compression quality levels
- Smart algorithms retain visual clarity
- Download all images as a single ZIP
- No watermarks added to compressed images
Two different ways to make an image smaller
"Too big" can mean two different things, and they have different fixes. File size (measured in KB or MB) is what upload forms and email limits care about — this tool lowers it by re-encoding the image more efficiently. Dimensions (width and height in pixels) are what matter for fitting a layout or a profile photo, and to change those you want Image Resize. Often the fastest way to hit a strict limit is to resize a huge photo to sensible dimensions first, then compress: a 6000-pixel-wide phone photo almost never needs to stay that large for the web.
Choosing a target that keeps photos looking good
Compression works by discarding detail the eye barely notices, so moderate targets look identical to the original while aggressive ones begin to soften edges and add blocky patches in skies and gradients. Rough starting points:
Roughly how small to aim for
| What it's for | Sensible target | Notes |
|---|---|---|
| Website or blog images | 100–300 KB | Fast loading with no visible loss |
| Email and chat | 200–500 KB | Stays clear on any screen |
| Form / portal photo uploads | Match the stated limit | Set the exact KB cap the portal asks for |
| Archiving lots of photos | As small as still looks fine | Test one image before batch-compressing |
JPG, PNG, or WebP for the smallest file?
Format choice changes how small an image can realistically get. JPG is the most efficient option for photographs and is what this tool outputs. PNG is lossless and best for screenshots, logos, and sharp text, but it produces much larger files for photos. WebP usually beats both at the same visual quality and is ideal for websites that support it. If a PNG photo is stubbornly large, converting it to JPG or WebP shrinks it far more than compression alone ever could.
Frequently Asked Questions
Can I compress an image to an exact size like 200 KB?
Yes. Switch to Target file size and enter the size you want per image. We lower the JPEG quality, and if needed reduce the dimensions, to get as close to your target as possible. Output is JPEG. If a target is too small to reach, you get the smallest version we can make plus a note.
How much can image compression reduce file size?
On the Recommended setting, most JPEG images see 30–60% size reduction. PNG images vary more: detailed photos may reduce by 20–40%, while simple diagrams can shrink by up to 70%.
What image formats are supported?
JPG/JPEG, PNG, and WebP images are all supported. For HEIC photos from iPhone, use our HEIC to JPG tool first, then compress the resulting JPG.
Will the compressed image look different from the original?
On the Recommended setting, the visual difference is barely perceptible. Maximum Compression produces the smallest file but may show slight quality reduction on high-detail images when viewed at full size.
Can I compress multiple images at once?
Yes. Select multiple images using the file picker or drag-and-drop several files at once. All will be compressed and available as individual downloads or a ZIP.
Does compressing an image change its dimensions?
No. Image dimensions (width and height in pixels) are not altered by compression. Only the file size changes by encoding the same pixel data more efficiently.