XnConvert is a polished desktop tool from the team behind XnView. It handles batch image conversion across 500+ input formats, applies filters (resize, watermark, rotate, adjust levels), and saves presets — all without an internet connection.
ChangeThisFile approaches image conversion differently: a hybrid architecture where most image formats convert entirely in the browser (client-side, files never leave the device), with server-side fallback for formats that need heavier processing. And for programmatic use, a clean HTTP API. This is an honest comparison of both tools.
Quick verdict
For batch desktop image processing: XnConvert. Free, works offline, supports image filters and transformations, and handles 500+ input formats including many RAW camera formats.
For API-driven image conversion in an app: ChangeThisFile. One POST, file + target, source auto-detected. No desktop app to wrap, works from any language or platform.
For privacy-sensitive image conversion: ChangeThisFile's client-side routes process JPG, PNG, WebP, HEIC, AVIF, GIF, BMP, ICO, SVG, and more entirely in the browser — files never reach any server. XnConvert also processes locally, but only on your installed machine.
Pricing comparison
| Plan | ChangeThisFile | XnConvert |
|---|---|---|
| Free tier | 1,000 conversions/month (no card) | Fully free for personal use |
| Commercial use | $29/mo Hobby and up | Paid license required for commercial |
| Browser tool | Free, no signup, no limit | Not available (desktop only) |
| Platform | Any (HTTP) | Windows, macOS, Linux (desktop) |
| Install required | No | Yes |
Feature comparison
| Feature | ChangeThisFile | XnConvert |
|---|---|---|
| HTTP API | Yes | No |
| Client-side (browser) conversion | Yes — 161 routes, files stay in browser | No (desktop install required) |
| RAW camera formats (CR2, NEF, ARW, etc.) | Limited | Excellent — 500+ input formats |
| Image filters (resize, watermark, etc.) | No — conversion only | Yes — extensive filter pipeline |
| Batch processing GUI | No GUI batch | Yes — core feature |
| Video/audio/document conversion | Yes — 690 total routes | No — image focused |
| Ebook/archive conversion | Yes | No |
| Commercial license | Subscription | Separate paid license |
Developer experience
ChangeThisFile API — the endpoint is the SDK. No install, no bindings, no wrapper. One POST with file and target. Source format is auto-detected from the filename extension.
curl -X POST https://changethisfile.com/v1/convert \
-H "Authorization: Bearer ctf_sk_your_key" \
-F "file=@photo.heic" \
-F "target=jpg" \
--output photo.jpg
The same call works identically from Python, Node, Ruby, Go, PHP — any HTTP client. For common image types, ChangeThisFile can also do the conversion client-side in the browser, meaning no file is ever uploaded. Get a free key at changethisfile.com/v1/keys/free.
XnConvert has no API. To use it programmatically, you'd need to invoke the CLI binary, parse its output, and manage file paths yourself. It's designed for interactive desktop use, not embedding in services.
When to choose which
| Use case | Recommended |
|---|---|
| Batch converting a folder of RAW photos | XnConvert (better RAW support) |
| Resizing, watermarking, or filtering images | XnConvert (image filter pipeline) |
| Offline image conversion on your own machine | XnConvert (free, no internet) |
| API call from a web backend | ChangeThisFile |
| Privacy-sensitive images (client-side conversion) | ChangeThisFile (browser routes) |
| Mixed file types (images + docs + video) in one API | ChangeThisFile |
| HEIC to JPG in a mobile web app | ChangeThisFile (client-side heic2any) |
Honest take
XnConvert is excellent for its designed use case — batch processing images on your own machine, especially RAW formats. It has a real filter pipeline (resize, adjust levels, watermark, add text) that ChangeThisFile doesn't match.
ChangeThisFile doesn't try to replace XnConvert for desktop batch work. It wins when image conversion needs to happen in a browser or a backend — especially with its client-side architecture where HEIC, AVIF, WebP, and standard image formats convert entirely in the browser without uploading. For mixed-format pipelines (images + documents + videos in the same API), ChangeThisFile covers all of it without switching tools.
If you're batch converting images on your own machine and need a filter pipeline or RAW format support, XnConvert is a better choice than paying for an API. If you're building something that converts images in a browser or backend, ChangeThisFile's free API tier gets you going in minutes — and many image routes never even upload the file.