Free Image Compressor
Compress images to a smaller file size for faster websites and easier sharing. Pick a quality and format, see exactly how much space you save, and download — all privately in your browser.
What is the image compressor?
An image compressor is a free tool that reduces the file size of an image so it loads faster and is easier to share or upload. It re-encodes your picture at a chosen quality level — and optionally a more efficient format like JPG or WebP — cutting the file size while keeping it looking good. Slashit's compressor runs entirely in your browser, so your images are never uploaded to a server and stay private on your device. You can compress several images at once, pick the output format, and see exactly how many kilobytes you save before downloading.
How our free image compressor works
Add your images
Drag JPG, PNG or WebP images onto the drop zone, or click to choose them.
Choose quality & format
Set the quality slider and pick JPG, WebP or PNG output — WebP and JPG compress the most.
Download the smaller files
See the size saved for each image, then download one or the whole batch.
What can you use the image compressor for?
Making a website load faster
Images are usually the heaviest thing on a page. Compressing them before upload is the single most effective fix for a poor Largest Contentful Paint score, and it costs nothing.
Getting under an email attachment limit
Most mail providers cap attachments around 20–25 MB. A folder of phone photos blows past that instantly; compressing to 70% quality typically brings a dozen photos comfortably under the limit.
Uploading to a form with a size cap
Passport applications, insurance claims and job portals often cap uploads at 1–2 MB per file. Drop the quality until the readout shows you're under the limit.
Freeing up storage
Compressing an archive of photos you only view on screen can reclaim most of the space they occupy without a visible difference.
Speeding up a slow email newsletter
Heavy images cause slow-loading newsletters and higher spam scores. Compressed images render faster in the inbox.
Who uses our free image compressor?
Website owners
Shrink images to improve page speed and Core Web Vitals.
Email & form users
Get under attachment and upload size limits.
Social & content teams
Keep uploads fast without an obvious drop in quality.
Why use the image compressor?
See your savings
Each image shows its before/after size and the percentage saved.
Format control
Compress to JPG or WebP for the smallest possible files.
Private & free
No sign-up, and images are processed entirely in your browser.
Which output format should you compress to?
The format matters as much as the quality slider. Here's how the three options behave.
| Format | Compression | Transparency | Best for |
|---|---|---|---|
| JPG | Strong, lossy | No | Photographs, and anything you'll email or upload |
| WebP | Strongest, lossy | Yes | Images for your own website — smallest files at the same quality |
| PNG | Lossless only | Yes | Logos, screenshots and graphics where sharp edges matter |
Tips for getting the best results
70–80% is the sweet spot
Below about 60% you start to see blotchy patches in skies and skin tones. Between 70% and 80% most photos lose half their size or more with no visible change.
Judge quality at full size
A compressed photo always looks fine as a thumbnail. Open the preview at full size before deciding you've gone far enough.
Resize before you compress
If a 4000px photo will only ever be displayed at 1200px, resizing it first saves far more space than compression alone. Use the image resizer, then compress.
Choose WebP for your own website
Every modern browser supports WebP, and it beats JPG by roughly a third at the same quality. Only avoid it if something in your workflow can't read it.
Keep your originals
Compression is one-way. Always work from a copy so you can go back if you compress too aggressively.
Common problems and how to fix them
My PNG barely got smaller
PNG is lossless, so the quality slider has very little effect on it. Switch the output format to JPG or WebP to get a real size reduction.
The compressed file is bigger than the original
This happens when the source is already heavily compressed, or when you compress a simple graphic to JPG. Try WebP, or leave that particular image alone.
The image looks blotchy or washed out
The quality is set too low. Raise the slider — your original file is untouched, so you can re-compress as many times as you like until it looks right.
Nothing happens with a very large image
Extremely large files (50+ megapixels) can take several seconds because the work happens on your device. Give it a moment; on an older phone it may take longer.
Frequently asked questions
How much smaller will my images get?
It depends on the image and quality you choose, but photos often drop 50–80% in size at a quality level where the difference is hard to see.
Which format compresses best?
WebP usually produces the smallest files at a given quality, followed by JPG. PNG is lossless, so it compresses far less.
Are my images uploaded?
No — compression happens in your browser, so your images never leave your device.
How much can I compress an image without losing quality?
For most photographs you can cut 50–70% of the file size at around 80% quality before any difference becomes visible at normal viewing size. Graphics with flat colour and text tolerate far less.
Does compressing an image reduce its dimensions?
No. Compression reduces file size while keeping the same width and height. If you also want fewer pixels, use the image resizer first.
Can I compress several images at once?
Yes. Drop in a whole batch — each one shows its own before and after size, and there's a running total of how much you've saved overall.
Is it safe to compress private or client photos here?
Yes. The compression happens entirely inside your browser using your device's own processor, so the images are never uploaded to any server.
What's the difference between compressing and resizing?
Compressing keeps the same dimensions but stores the image more efficiently. Resizing changes the actual pixel dimensions. Combining both gives the smallest possible file.
