ChangeThisFile vs Convertio: Honest Comparison

Convertio is one of the most-visited online converters. It's polished, covers a wide range of formats, and has a decent free web experience. The question is whether its pricing and server-only architecture fit your workflow.

ChangeThisFile was built to eliminate two common frustrations with online converters: the lack of a real free API tier, and the fact that every file — even a simple image resize — has to upload to someone's server. This comparison covers both tools honestly.

Quick verdict

For casual file conversion: Both tools work. ChangeThisFile requires no signup at all; Convertio requires an account for larger files or API access.

For privacy-sensitive files: ChangeThisFile wins on common image and data formats — they convert in your browser, nothing uploads. Convertio is server-side only.

For API access: ChangeThisFile has a free tier (1,000/mo, no card). Convertio's API requires a paid plan.

For large files: Convertio's free tier allows 100MB. ChangeThisFile's browser tool has no fixed server-side limit for client-side routes (limited by your RAM); API uploads are 25MB free.

Pricing comparison

Convertio's $9.99/mo entry plan is inexpensive for occasional personal use with larger files. But if you need API access or are building a product on top of conversions, ChangeThisFile's free tier means you can prototype and ship without a credit card.

Feature comparison

Format coverage

Convertio claims 300+ supported formats, including some niche formats not commonly supported elsewhere. Their coverage includes CAD formats, e-book formats, 3D models, and specialized image types.

ChangeThisFile covers 634 source→target pairs across 82 formats. The focus is on the high-volume routes: all major image formats (JPG, PNG, WebP, HEIC, AVIF, SVG, BMP, GIF, ICO, TIFF, PSD), documents (PDF, DOCX, ODT, RTF, HTML, Markdown), spreadsheets, video, audio, ebooks, archives, and fonts.

For mainstream conversions, coverage is comparable. Convertio likely has more niche format support. ChangeThisFile has more explicit routes, making it easier to know exactly what's supported.

Privacy and data handling

Convertio is entirely server-side. Every conversion — including a simple PNG-to-JPG — uploads your file to their servers. They state files are deleted after a period (check their current policy), but the upload happens regardless.

ChangeThisFile client-side routes run in your browser using JavaScript. For the 161 client-side routes (covering all major image formats, JSON/YAML/CSV/TSV/XML/TOML, HTML/Markdown, DOCX→HTML, HEIC, PSD, fonts), your file is never transmitted anywhere. The conversion happens on your CPU, in your browser tab.

For server-side routes (video, audio, complex documents, archives), ChangeThisFile uploads over HTTPS and auto-deletes after conversion. The behavior is similar to Convertio for those formats.

API and developer experience

Convertio has a REST API, but it requires a paid plan. The API uses a job-based model: create a conversion, poll for status, download the result.

ChangeThisFile's API is synchronous and available free:

curl -X POST https://changethisfile.com/v1/convert \
  -H "Authorization: Bearer ctf_sk_your_key" \
  -F "file=@input.png" \
  -F "source=png" \
  -F "target=webp" \
  --output result.webp

Get a free API key at changethisfile.com/v1/keys/free — no card, no account setup beyond a single request. The response is the converted file directly, no polling needed.

For developers prototyping a feature or building a small integration, ChangeThisFile's API removes the friction of a credit card before you know the tool works for your use case.

When to choose which

Convertio is a solid tool, especially if you need Google Drive integration or batch conversions. But if you're looking for a free API starting point or care about not uploading sensitive files, ChangeThisFile is the better fit. Get a free API key and test it in under a minute — no card needed.