Convertio is a versatile online converter that handles hundreds of formats — images, documents, audio, video and more. Privatool covers the most common conversions, but with one crucial difference: everything runs inside your browser, so your files are never uploaded. Here's how they compare.
Side-by-side comparison
| Feature | Privatool | Convertio |
|---|---|---|
| Image format conversion (JPG/PNG/WebP) | ✅ Client-side | ✅ Server-side |
| PDF ↔ image | ✅ Client-side | ✅ Server-side |
| Exotic formats (video, audio, ebooks) | ❌ | ✅ 300+ formats |
| Files uploaded to server | ❌ Never | ✅ Yes |
| Free file size limit | Limited only by your RAM | 100 MB |
| Free daily conversions | Unlimited | 10 files/day |
| Account required | ❌ Never | ❌ (limited) |
| Works offline | ✅ After first load | ❌ |
Where your file actually goes
Convertio uploads your file to a cloud server, converts it there, and offers the result for download. Their policy is to delete files after 24 hours, but the file still leaves your device and sits on a third-party machine in the meantime.
Privatool converts using JavaScript and WebAssembly running in the page itself. For a JPG-to-PNG or PDF-to-image conversion, the bytes never leave your RAM — a difference you can verify by watching your browser's Network tab.
When to choose Convertio
- You need to convert video, audio, ebook, or CAD formats Privatool doesn't support
- You're converting between two rare formats and need maximum coverage
- The file is huge and your device is low-powered
When to choose Privatool
- Your files are private, confidential, or client work
- You do frequent image or PDF conversions and hit Convertio's 10/day free cap
- You want instant conversion with no upload wait
- You're offline or on a locked-down network
Bottom line
For the everyday image and PDF conversions most people need, Privatool does it privately and without daily limits. Convertio remains the tool to reach for when you need its enormous catalog of exotic formats.
Why 300+ formats requires a server
Convertio's format catalogue is its main advantage, and the reason for it is structural rather than a matter of effort.
Converting video or audio means running a full codec stack — H.264, HEVC, AV1, AAC, Opus — each a large, heavily optimised native library. Ebook formats need document layout engines. CAD formats need geometry kernels. Doing this on a server means installing FFmpeg, Calibre, and similar tools once and reusing them for every user.
Doing it client-side means shipping those engines to every visitor. FFmpeg compiled to WebAssembly runs to tens of megabytes before your file is touched — the exact size depends on the build and which codecs are included — and it runs slower than a native build. For a single conversion, the download often costs more time than the upload it replaces.
So the trade is not "Privatool has fewer features because it is newer". It is that a no-upload guarantee sets a hard ceiling on which conversions are practical. Image and PDF work fits comfortably under it; video does not.
Where the size limits actually bind
The comparison table shows Convertio capped at 100 MB free and Privatool bounded by device RAM, which sounds like a straightforward win. In practice it depends on the device.
A desktop with 16 GB of RAM handles files far beyond 100 MB without issue. A five-year-old phone may fail on a 200 MB file that Convertio's servers would process without noticing, because the browser tab has a memory ceiling and hitting it kills the tab rather than degrading gracefully.
The rule of thumb: on a laptop or desktop, client-side wins on both privacy and speed. On constrained mobile hardware with a very large file, borrowing a server's memory is a legitimate reason to upload.
The 10-conversions-a-day limit
Convertio's free tier allows 10 files per day, which resets on a 24-hour cycle. For occasional conversions this is invisible. It becomes a wall on batch work — converting a folder of images for a website, or a set of screenshots for documentation — where you finish the eleventh file the next morning.
Privatool has no daily cap because there is no server cost per conversion; the work happens on your machine.
Frequently asked questions
Is conversion quality the same?
For image formats, yes — both use standard encoders and the output for a JPG-to-PNG or PNG-to-WebP conversion is equivalent. Convertio exposes more fine-grained quality controls for exotic formats, which is where its depth shows.
What happens to my file on Convertio?
It is uploaded, converted on their infrastructure, and made available for download. Their stated policy is deletion after 24 hours. That is a normal arrangement; the point of this comparison is that client-side processing removes the need to evaluate it at all.
Can Privatool convert HEIC photos from an iPhone?
Yes, HEIC to JPG and PNG runs client-side. This is a good example of where privacy matters in practice, since iPhone photos frequently carry GPS coordinates in their metadata.
Why is the first conversion slower on Privatool?
The conversion engine downloads to your browser on first use, then caches. Subsequent conversions start instantly with no upload wait, which is normally faster overall.
Which should I use for client work?
Privatool for anything covered by an NDA or containing personal data — the file never leaves your device, so there is nothing to disclose. Convertio when you need a format Privatool does not support and the content is not sensitive.