Bytescale targets developers building apps where users upload files — it handles storage, CDN delivery, image transformations, and basic video processing in one platform. ChangeThisFile focuses exclusively on conversion: send a file in one format, receive it in another, without any hosting or delivery layer.
Both have upload-based APIs and cover image transformations, so they look similar on the surface. The key difference is what happens after the conversion: Bytescale stores and serves files; ChangeThisFile returns them and you own the storage.
Quick verdict
For apps that accept and serve user-uploaded files: Bytescale. Managed storage, CDN, upload widget, and transformations in one platform.
For converting files without managing hosted storage: ChangeThisFile. Simpler pricing, broader format coverage, and no storage overhead.
For document and archive conversion: ChangeThisFile. Bytescale's non-image/video coverage is limited.
For the simplest API integration: ChangeThisFile — no storage setup, one POST with file + target. Source auto-detected from filename.
Pricing comparison
Competitor pricing below is as of April 2026 - check the vendor's current pricing page before deciding.
| Plan | ChangeThisFile | Bytescale |
|---|---|---|
| Free tier | 1,000 conversions/month (no card) | Quota-based free tier |
| Entry paid | $29/mo — 10,000 conversions | $9/mo — includes storage + bandwidth |
| Mid tier | $99/mo — 50,000 conversions | $49/mo — more storage + bandwidth |
| High volume | $499/$1,999/mo | Custom/enterprise |
| Pricing model | Per conversion (flat count) | Uploads + storage GB + bandwidth GB |
| File hosting included | No (convert and return) | Yes — files stored on Bytescale CDN |
Bytescale bills for uploads, storage, and bandwidth together — you pay to keep files on their platform. ChangeThisFile has no storage component; you receive the converted file in the response and store it yourself. For workflows where you already have storage (S3, R2, local), ChangeThisFile avoids paying twice for hosting.
Feature comparison
| Feature | ChangeThisFile | Bytescale |
|---|---|---|
| Free API tier | Yes — 1,000/mo, no card | Yes (limited quota) |
| SDK required | No — curl/fetch/requests directly | Optional JS/React upload SDK |
| Image conversion | Yes — 690 image routes | Yes — URL-parameter transforms |
| Video conversion | Yes (MP4, WebM, MKV, AVI, MOV) | Yes (video processing add-on) |
| Document conversion | Yes (PDF, DOCX, XLSX, EPUB) | Limited |
| Archive conversion | Yes (ZIP, RAR, 7Z, TAR) | No |
| CDN hosting | No | Yes |
| Upload widget | No | Yes (React/JS components) |
| Client-side conversions | Yes — 161 browser-native routes | No |
| HMAC webhooks | Yes | Yes |
| Async jobs | Yes (files >100MB) | Yes |
Format and route coverage
Bytescale focuses on image transformations (resize, crop, format, compression) and has video processing capabilities. Its strengths are image URL transforms and a well-designed upload widget for React and vanilla JS. Document and archive support is limited.
ChangeThisFile covers 690 specific conversion routes across 9 categories. Stronger on breadth: full document conversion via LibreOffice (DOCX, ODT, RTF, HTML, PDF), ebook conversion via Calibre (EPUB, MOBI, AZW3, FB2), archive cross-conversion via 7-Zip (ZIP, RAR, 7Z, TAR), audio conversion via FFmpeg (MP3, WAV, FLAC, AAC, OGG), and data format conversion (CSV, JSON, YAML, XML, TOML) — 161 routes of which run entirely in the browser with no upload.
API and developer experience
Bytescale provides React and JavaScript SDKs for its upload widget, plus a REST API for server-side operations. The upload widget handles drag-and-drop, progress tracking, and validation well. For building user-facing upload flows, the widget significantly reduces boilerplate.
ChangeThisFile API skips the SDK entirely. The endpoint is the SDK:
curl -X POST https://changethisfile.com/v1/convert \
-H "Authorization: Bearer ctf_sk_your_key" \
-F "file=@video.avi" \
-F "target=mp4" \
--output result.mp4
Source format is auto-detected from the filename. No setup, no dependencies. Get a free key at changethisfile.com/v1/keys/free. Supports idempotency keys (Stripe-style) and HMAC-signed webhooks for async jobs on large files.
When to choose which
| Use case | Recommended |
|---|---|
| User file upload widget for a web app | Bytescale |
| Host and serve user files from a CDN | Bytescale |
| Format conversion without managed storage | ChangeThisFile |
| Document, ebook, or archive conversion | ChangeThisFile |
| Simple API — curl or fetch directly, no package install | ChangeThisFile |
| Privacy-first — files stay in browser | ChangeThisFile (client-side routes) |
| React upload component with built-in UI | Bytescale |
Bytescale is a solid platform for apps that need to accept, store, and transform user uploads — especially if you want a polished React upload widget. But if your use case is format conversion without managed hosting, or you need document/ebook/archive routes, ChangeThisFile's free tier is a simpler fit. 1,000 free conversions/month, no storage overhead.