Conversion API for AI builders.
688 formats. Flat pricing.
One API. Every format. No per-format fees, no per-page parsing tax, no surprise overages. Free up to 25 conversions a month, paid plans from $29/mo — from $0.019/conversion, well under industry norms at every tier.
- 25 conversions/month
- 25 MB max file size
- 10 req/min rate limit
- Hard-stops at quota
- Email support
- 1,500 conversions/month ($0.019/conversion)
- 100 MB max file size
- 60 req/min rate limit
- Hard-stops at quota — no overage billing
- Email support
- 6,000 conversions/month ($0.017/conversion)
- 100 MB max file size
- 120 req/min rate limit
- Hard-stops at quota — no overage billing
- Priority email support (1 business day)
- 40,000 conversions/month ($0.012/conversion)
- 100 MB max file size
- 600 req/min rate limit
- Hard-stops at quota — no overage billing
- Private Slack channel
- 200,000 conversions/month ($0.010/conversion)
- 100 MB max file size
- 3,000 req/min rate limit
- Hard-stops at quota — no overage billing
- Named contact, weekly check-ins
Self-hosted deployments, custom format engines, and a written uptime SLA with service credits — terms scoped in contract. Built for high-volume platforms with strict residency or compliance requirements.
Why ChangeThisFile API
Built for builders who need conversion to be a one-line dependency, not a project.
Image, video, audio, document, spreadsheet, ebook, archive, font. Pass source and target as extension strings — we handle the engine routing (FFmpeg, LibreOffice, Calibre, Sharp, 7-Zip) for you.
Every format costs the same. PDF-to-DOCX, PSD-to-WebP, MKV-to-MP4 — one conversion equals one count against your monthly quota. No per-page tax, no per-format multiplier.
Files are deleted from our servers immediately after conversion. We never train models on your data and we never share files with third parties. Audit logs available on Scale and above.
Image, data, and spreadsheet conversions complete in under 500 ms at the median. Long-running formats (large video, ebook bundles) move to the async /v1/jobs endpoint automatically.
Frequently asked questions
Still have a question? Email support@changethisfile.com.
Can I change plans?
Yes. Upgrade or downgrade any time from the dashboard. Changes take effect immediately and we prorate the difference on your next invoice. Annual plans are non-refundable but can be paused or migrated to a different plan at renewal.
What happens if I exceed my quota?
Every plan hard-stops at its monthly quota unless the account has prepaid conversion credits. There is no automatic overage billing, so a traffic spike cannot silently increase the invoice. Add credits, upgrade, or wait for the next calendar-month reset. To see where you stand, call GET /v1/usage, which returns conversions_this_month alongside monthly_limit.
Is there a free tier?
Yes. The free tier includes 25 conversions a month, a 25 MB file size cap, and 10 requests per minute — enough to evaluate the API, with day passes and paid plans for real volume. No credit card required. Request a key with your email, then follow the verification link to reveal it through a short-lived, account-bound reference.
How do I get an API key?
Two ways. Programmatically: curl -X POST https://changethisfile.com/v1/keys/free -H "content-type: application/json" -d '{"email":"you@example.com"}' sends the verification link. Through the UI: visit the dashboard and request the same verified-email flow.
What is the SLA?
We operate against a 99.5% monthly availability target, monitored by automated canaries every 15 minutes plus a nightly end-to-end smoke test — details on the reliability & SLA page. Written, contractual SLAs with service credits are available on Startup plans and above: email support@changethisfile.com to put one in place. Live health is always visible on the status page.
Do you train on my files?
No. Files are deleted from our servers immediately after the conversion completes (async jobs: within 24 hours). We never train models on customer data, we never share files with third parties, and we never read the contents of your files outside the conversion path itself. Details are on the security page, and a signable Data Processing Addendum with EU Standard Contractual Clauses is available on request.
Can I self-host?
Self-hosting is available on the Enterprise plan. We ship a Docker compose stack with all conversion engines (FFmpeg, LibreOffice, Calibre, Sharp, 7-Zip) and you run it inside your VPC. Email aadil@changethisfile.com to scope a deployment.
Does the API support async / large files?
Yes. POST /v1/convert processes files under 100 MB inline and automatically queues larger files to async — you get back HTTP 202 with a job_id to poll. POST /v1/jobs always queues regardless of size, for callers that prefer predictable async behaviour. Full schema is in the OpenAPI spec.
How do I get support?
Free and Hobby tiers get email support at support@changethisfile.com — typical response time is 24–48 hours. Startup and above get priority response within one business day. Scale and Growth get a private Slack channel and a named contact who knows your stack.
Can I pay annually for a discount?
Yes. Annual plans are billed once a year at a 20% discount versus the monthly rate. Toggle the billing interval at the top of this page to see annual pricing. You can switch from monthly to annual at any time from the dashboard.
Get a free API key in 30 seconds
No credit card. 25 conversions a month, every month, for free. Day passes and plans when you need more.