Best Free Image Converters Compared (2025)

There are dozens of free image converters out there. Most of them do basically the same thing—let you convert between formats like HEIC, WebP, JPG, and PNG. But how they do it varies a lot, especially when it comes to privacy.

I tested a bunch of them. Here's what I found.

The big names

CloudConvert — Powerful, supports tons of formats. But uploads your files to their servers. Has usage limits on free tier. Privacy policy says files are deleted after 24 hours, but you're trusting them on that.

Zamzar — Been around forever. Also server-side processing. Free tier limited to 2 files at a time and 50MB max. Files stored on their servers.

Convertio — Similar deal. Server-side, has limits, stores your files temporarily. Interface is clean but ad-heavy on free tier.

iLoveIMG — Popular, easy to use. Server-side processing. Free tier has daily limits. Lots of upselling to premium.

FreeConvert — Server-side. 1GB file size limit which is generous. Files say they're deleted after a few hours.

The pattern

Notice something? They all work the same way: upload to server, process, download result. Your files leave your device and sit on their infrastructure.

This business model makes sense from their perspective. They can:

• Enforce limits to push paid tiers
• Track usage for analytics
• Potentially monetize data in other ways

But from a privacy standpoint it's not ideal. You're sending potentially personal photos to servers you don't control.

The alternative approach

Some converters work differently—processing files entirely in your browser without any upload.

Squoosh (by Google) — Client-side, privacy-respecting. Open source. But focused on compression/optimization, not format conversion. Limited format support.

CovertConvert (this site) — Full disclosure, I built this one. Client-side processing, supports HEIC/WebP/AVIF/TIFF/PNG to JPG or PNG. No uploads, no accounts, no limits. Your files stay on your device.

The technical approach matters because it's not just a promise—it's architecturally impossible for client-side tools to see your files. You can verify it yourself in browser dev tools.

What I'd actually use

Depends on what you need:

For common formats (HEIC, WebP, PNG, etc.): A client-side tool like this one. No privacy concerns, no limits, fast.

For obscure formats or complex conversions: CloudConvert has the widest format support. Just be aware your files are going to their servers.

For batch processing at scale: If you're doing thousands of files regularly, desktop software might make more sense than any web tool.

The bottom line

Most free converters work fine functionally. The main differences are:

1. Privacy (client-side vs server-side)
2. Limits (file size, daily quotas)
3. Ad intensity
4. Format support

For everyday HEIC/WebP/PNG conversion, you don't need to upload your files anywhere. Client-side tools exist and work just as well, without the privacy tradeoff.