Photo Editor · Windows 10 and 11
Compress images without uploading them
Choose JPG or WebP, slide the quality down, and Octoolo shows about how many kilobytes the file will be before you save it. The work happens on your PC, so your photos never pass through someone else's server.
How to compress an image
- 1
Load the photo
Open it in the Photo Editor with File › Open…, or drag it onto the window from File Explorer. Crop it now if it needs it, since a crop also makes the file smaller.
- 2
Choose JPG or WebP
Press Export (Ctrl Alt Shift W). Under Kind of file, choose JPG or WebP. PNG has no quality setting, so it is not the one for a small file.
- 3
Lower the quality
Move Quality, which runs from 30 to 100. A moment later the line below shows about how big the file will be.
- 4
Shrink it further if needed
Still too big? Pick a smaller width under Size, then press Save and choose where the copy goes.
Two ways to compress
Export suits a photo you have edited. It works out the size from a smaller copy of the picture, which is why it says “about”. For a picture you only want smaller, File › Many pictures at once… has Make smaller, also on the start page as Make pictures smaller. It makes the whole file each time you change a setting and puts the original and the result side by side:
- WebP (smallest), chosen at first, or JPG (everywhere).
- Longest side in pixels, to shrink big photos as you compress. 0 keeps the size.
- Quality from 10 to 100, starting at 85.
Under the result you see the original's size, the new size and the change in percent. If it shows a plus sign, the original was already more compressed than your settings: keep the original, or lower the quality. The copy is saved as “photo-compressed.webp” or “.jpg”. Drop several pictures and the same quality applies to all: each row has Save, Save all as ZIP saves them together, and Open other pictures starts over.
Which quality to pick
| Quality | Use it for |
|---|---|
| 90 to 100 | Photos you will print or edit again |
| 80 to 89 | Sharing, websites and email; hard to tell from the original |
| 60 to 79 | Smaller attachments and previews; check skies and edges |
| Below 60 | Thumbnails; blocks and smudges start to show |
The numbers are not one shared scale: WebP at 80 and JPG at 80 give neither the same look nor the same size, so judge the result, not the number.
Compression is kindest to photos. Screenshots, charts and pictures of text get fuzzy edges at quality levels where a photo still looks fine, so keep the quality high for those, or keep them as PNG. For a closer look at JPG settings, see compress JPEG.
When a file must be under a set size
Many upload forms cap the file, at 200 KB or 2 MB for example. Octoolo has no “make it under this size” button, but it shows the size as you change the settings, so you can get there in two moves:
- Fewer pixels first. Unless the form asks for a large picture, pick 1600 or 1280 under Size in Export, or set Longest side to that number in Make smaller.
- Then the quality. Lower it in small steps and watch the size until it drops under the limit. Leave a little room, since Export's figure is an estimate; Make smaller shows the exact size.
Cutting pixels usually saves far more than cutting quality, and at normal viewing sizes it costs less of the picture. Halving the width leaves a quarter of the pixels to store.
WebP, JPG or PNG?
WebP gives the smallest file of the three for the same look, and it keeps transparency. Every current browser shows it, but some older programs and upload forms still refuse it. For pictures on a website you run, it is the natural choice.
JPG opens everywhere, which keeps it the safe choice for email, forms and printing. It has no transparency, so clear areas turn white, or the color you pick under See-through parts become in Export.
PNG is lossless. Octoolo saves it without a quality setting and does not squeeze PNG files further, so a photo saved as PNG stays large. To make a PNG smaller, save it as WebP, which keeps its clear areas, or as JPG if it has none. The PNG to WebP and PNG to JPG pages cover both.
Whichever you pick, the compressed copy carries no location or camera details, so it is ready to share.
Octoolo or an online tool?
| Detail | Octoolo | A typical online tool |
|---|---|---|
| Your files | Stay on your computer | Usually uploaded to the site's server |
| Without internet | Works | Does not work |
| File size | No limit | Often capped on free use |
| Watermarks and ads | None | Common on free plans |
| Cost | $4.99 a month, all 17 apps | Free with limits, or a plan per site |
Questions, answered
How much smaller will my photo get?
That depends on the photo and the settings, which is why Octoolo shows the size before you save. A large phone photo resized to 1920 pixels and exported at quality 85 usually ends up a fraction of its original size.
Can I compress PNG files?
Not as PNG: Octoolo writes PNG without loss and has no PNG squeezing. Save it as WebP, which keeps transparency, or as JPG if it has no clear areas.
Can I compress many images at once?
Yes. Drop or choose them all in File › Many pictures at once…: the same quality applies to every one, each row has Save, and Save all as ZIP saves them together.
Can I see the compressed result before saving?
Yes, in Make smaller (File › Many pictures at once…), which shows the compressed picture next to the original with both sizes. Export shows the size, but not a preview of the compression.
Does compressing change the width and height?
Only if you ask it to. Quality alone keeps the dimensions and changes how much detail is stored; Size or Longest side changes the dimensions.
Is my photo sent to a server to compress it?
No. The compression runs inside Octoolo on your PC; nothing is sent anywhere, and it works with no internet connection.
Image compressor, and 16 more apps.
Download for Windows7 days free, then from $3.99 a month for all 17 apps. Windows 10 and 11.