Compress Image Online: Reduce Photo Size in KB with Convertavo
Convertavo's free image compressor makes photos smaller without making them blurry. Most images come out 60 to 80% lighter, and you won't see a difference. Add JPG, PNG or WebP files up to 25 MB, pick a quality, and download.
- ✓ No signup
- ✓ No watermark
- ✓ Deleted after 1 hour
Working out the difference…
Dark means unchanged. The brighter an area, the more compression changed it — differences are amplified ten times so they show at all.
Drag the divider, or use the arrow keys. Zoom to 100% to check fine detail — that is where compression shows first.
Compress on this devicePrivate mode: the images never leave your phone or computer
Your browser compresses the images itself, so nothing is uploaded and no credits are used. Location data is always removed. The main compressor above is smarter — it finds the best quality for each image and never makes one bigger — but this is here when privacy comes first.
Your files stay private
Uploads are deleted from our servers one hour after processing. Nothing is read or reused, and nothing is kept unless you save it to your account.
No account required
20 free credits a day, with no email address and no watermarks on the output.
Runs on any device
Works in any modern browser on Windows, macOS, Linux, Android and iOS.
How to compress an image online
You don't need an account for any of this.
- STEP 01
Add your images
Choose files or a whole folder, paste a link, or paste an image. Each file can be up to 25 MB.
- STEP 02
Choose a quality level
Tap a quick preset, set a target size in KB, or pick the quality yourself. For images on a website, 82 is a good number.
- STEP 03
Compress and download
Click Compress images. A batch is normally ready in 4 to 10 seconds, and you can save the images one at a time or grab a single zip.
We'd drag the before-and-after slider across the picture first. It's the quickest way to spot any change.
What the Compress Image tool does
A whole folder at once
Drop in a folder and every picture inside gets compressed. Up to 100 at a time on the biggest plan.
Check before you download
Drag a slider across the before and after, or switch to a view that lights up what changed.
Location data removed
Phone photos often store where they were taken. That gets stripped by default.
How to reduce image size in KB for online forms
Exam sign-ups, job portals and passport or visa forms often won't take a photo over 100 KB. Some want 50 KB, and a few ask for 20 KB. To compress an image down to that:
- Tap the Forms · under 100 KB preset, or choose Target file size.
- Type the number the form asks for, like 50.
- Click Compress images and download the smaller photo.
The tool keeps as much quality as it can while getting under your number. If lowering the quality isn't enough, it makes the picture a bit smaller in pixels too. Every result says whether the target was met.
What quality should I pick when I compress a photo?
We ran one photo through the slider to show you. It started at 326 KB.
Up at 90 to 100, it looked exactly like the original, but the file barely got any smaller, so there isn't much point. Between 75 and 85 is where we'd stay for websites and sharing. At 82 the photo came down to 118 KB, and we couldn't spot a difference at normal size.
At 50 to 70 it was 54 KB, and you could start to see it in the smooth parts, like the sky. That's fine for a small thumbnail. Below 50 we got it down to 22 KB. By then there were little blocks all over the sky, so we wouldn't bother.
Can I compress an image without losing quality?
For photos, near enough, as the test above shows.
Screenshots and logos behave differently. Save one as a JPG and you'll often see a faint smudge around the letters. We keep those as PNG or WebP.
And if not a single pixel can change, there's Lossless mode. It hands back exactly the same pixels, only stored more tightly.
Which compression setting should I use?
There are five modes, and we'd leave it on Smart unless you have a reason not to. It tries each image at different qualities and stops at the lowest one that still looks like the original.
Maximum squeezes harder. You might lose a little fine detail with it, so we'd keep it for thumbnails and previews. With Lossless, nothing changes at all, down to the last pixel. Custom quality lets you pick the number yourself, and Target file size brings every image under the KB limit you type.
Quick presets set everything in one click
- Website: WebP, up to 1920 px
- Email: JPG, up to 1280 px
- Social media: JPG, 1080 px
- Forms · under 100 KB: for exam, visa and job portals
- Smallest possible: Maximum mode, and the tool picks whichever format comes out smallest
- Print · no loss: Lossless, in the original format
Can I reduce image dimensions too?
Yes. A typical phone photo is about 4000 pixels across. Set Resize to 1920 and it comes out less than half as wide, which on its own makes the file a lot smaller. The same menu has other sizes from 3840 down to 800 pixels, percentages like 50%, or a width and height you type yourself.
If you only want to change the size, without compressing, use Resize Image.
Should I compress to JPG, PNG, WebP or AVIF?
We saved one of our test images four ways to see the difference. As a PNG it was 415 KB. As a JPG at quality 82 it came to 65 KB. With WebP it dropped to 23 KB. AVIF went a little further, to 21 KB. Try it on your own pictures and the sizes will be different, though for a photo PNG is nearly always the biggest.
| Your image | Best choice |
|---|---|
| A photo for a website | WebP or AVIF. In our test, both came out at about a third of the JPG. |
| A photo for email or old software | JPG. It's the safe one when you don't know what the other person will open it with. |
| A screenshot, logo or text | PNG or WebP. JPG would blur the edges of the letters a little. |
| A see-through background | PNG or WebP. Transparent images stay transparent. |
| An animated GIF | Animated WebP. It keeps moving and is often several times smaller. |
Not sure? Choose Smallest (auto). It runs the same kind of comparison on your image. Formats that would lose something it needs, like a see-through background, are skipped, and you get the smallest of the rest.
On a website, those smaller files load sooner. Google looks at how fast a page loads as part of its Core Web Vitals. Chrome, Safari, Firefox and Edge all open WebP and AVIF now.
Can I compress iPhone photos?
Yes. HEIC photos from an iPhone come out as JPG, so they open on any device. Their wider colour range is converted properly, so the colours don't look washed out.
How do I know how much quality I'm losing?
The moment you add an image, a preview shows up in the settings. When you move the quality slider, three things update:
- the picture on your screen
- the new file size, estimated before anything is uploaded
- a "visual quality kept" score out of 100, with a verdict from "Identical" to "Heavy loss"
After compressing you can compare in three ways. You can drag a line across the picture to wipe between the old and new versions, or put them next to each other. The one we use most is Difference. It lights up only the parts of the picture that changed.
We'd also zoom in to 100% or 200%. That is where compression shows first.
Is Convertavo's image compressor free and safe?
Is it free?
Yes. You get 20 free credits a day and each image uses 1 credit, so that's 20 images a day. No email, no watermark.
Free files can be up to 25 MB each. Standard plans and above also get priority processing.
Is it safe to upload my photos?
Uploads are deleted from our servers one hour after processing. We don't keep them, look at them or reuse them.
Phone photos often carry hidden EXIF data: the GPS location, the camera model and the date. Strip EXIF and location data removes all of it and is switched on by default. Worth keeping on before you post a photo taken at home.
Can I compress images without uploading them?
Yes. Open Compress on this device for private mode. Your browser does the work, so nothing is uploaded, no credits are used, and location data is always removed.
Does it work on my phone?
Yes. It runs in any modern browser on Windows, macOS, Linux, Android and iOS, so there's nothing to install.
Common mistakes when you compress images
The most common one is compressing the same image over and over. Each pass throws away a bit more detail and it adds up, so always go back to the original photo.
Saving screenshots and logos as JPG is another. Sharp edges pick up faint halos, so use PNG or WebP for those.
Going below quality 50 rarely pays off. Blocky marks appear and the file is only slightly smaller.
And if you send pictures by email, keep a JPG copy. Some email apps and older programs still struggle with WebP.
Need to compress an image right now? Drop it into Convertavo above and it'll be ready in a few seconds.
Compress imagesCommon questions about compressing images
The ones we get asked most.
How do I compress a photo to under 100 KB?
There's a preset called Forms under 100 KB that does it for you. You can also choose Target file size and type 100 yourself. The 326 KB photo in our example above came out at 97.2 KB, and its width and height didn't change.
Can I compress several images at once?
Yes. Signed out, you can add 3 at a time. Make a free account and that goes up to 10, and the biggest paid plan takes 100. If you've got a whole folder, drop the folder in. When it's done you can download them one by one or as a single zip.
Does compressing an image reduce its quality?
A little detail is removed, but at quality 75 to 85 you usually can't see it. Before you download, the preview gives each image a score out of 100, so you're not guessing.
Will a compressed image ever be bigger than the original?
No. If an image is already as small as it can get, you get it back unchanged, apart from removing its location data if that option is on.
Can I compress images without uploading them?
Yes. Open Compress on this device and your browser does the work. We never see those pictures, and you don't spend a single credit on them.
What is the best format for small images?
For photos, WebP or AVIF. In our test both came out at about a third of the JPG. JPG is still the better pick for email, and screenshots or logos look cleaner as PNG or WebP.
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