PDF24's online compressor uploads your file (deleted within an hour, it says) and has no KB target; at its default settings our 2.04 MB scan came out at 540.10 KB. CompressKaro compresses in the browser to the size you type (180.5 KB). PDF24 is free with no caps, has a lighter page than ours, and its Windows app PDF24 Creator works on your computer.
Side by side
| CompressKaro | PDF24 Tools | |
|---|---|---|
| Where the file is processed | In your browser; the file is never uploaded | Online tool: uploaded to PDF24 servers in the EU (POST to filetoolsNN.pdf24.org in our test), deleted within 1 hour (PDF24 FAQ). PDF24 Creator (Windows) runs locally |
| How you choose the size | Exact KB/MB target (12 presets + custom) | DPI and image quality fields (144 DPI, 75 % by default) |
| 200 KB test (a 2.04 MB scanned-style PDF (synthetic, no personal data)) | 180.5 KB (under the limit) | 540.10 KB at default settings (over the limit) |
| Price | Free, no account, no daily cap | Free, "thanks to advertising" |
| Page weight on a phone | 242 KB of JavaScript, 0 ad/tracker hosts | 137 KB of JavaScript (lighter than ours); an ad slot on the result page |
Where PDF24 Tools is better
- Lighter page than CompressKaro and completely free.
- A Windows desktop app (PDF24 Creator) that processes files on your computer.
- Fine control for experts (DPI, image quality) and many other PDF tools.
Where CompressKaro is better
- Type the portal's limit instead of guessing DPI and quality.
- The online tool uploads; CompressKaro never does, on any device including phones.
- Indian portal kits and Indian-language interface.
Which should you use?
On a Windows PC, PDF24 Creator is a good offline option. On a phone, or when you need an exact KB size, use CompressKaro.
How we tested
On 17 October 2026 we ran each tool in Chrome with the same synthetic 2.04 MB scanned PDF, measured the file each one produced for a 200 KB limit, and logged every network request that could carry the file. Numbers can differ with other files. Full method and its limits: how we test. Results for all tools: compare PDF compressors.
Sources
- CompressKaro test: output size and network log (method on /compare/how-we-test), checked 17 October 2026
- PDF24 Tools FAQ, checked 17 October 2026