It's a fair question to ask of any online PDF tool: you're uploading documents that might hold contracts, IDs, invoices, or signatures, and you want to know what happens to them. This post answers it plainly — how Blackpdf processes your files, what we keep and what we delete, how your account data is protected, and where you can verify all of it.
The short version: many operations never upload your file at all, the ones that do are encrypted in transit and deleted right after processing, and we don't retain copies of your documents. Here's the detail.
Where your files are actually processed
Not every tool works the same way, and the difference matters for privacy:
- In your browser. A large number of Blackpdf tools run entirely client-side, in JavaScript, on your own device. For these, your file never leaves your computer — it isn't uploaded anywhere. Tools like merging, rotating, enhancing scans, and many others do their work locally and just hand you the result.
- On our servers, then deleted. Some operations are too heavy to run in a browser — OCR, compression, and some conversions. For these, the file is uploaded over an encrypted connection, processed in an isolated environment, and automatically deleted as soon as it's done.
Either way, the outcome is the same: we don't keep your documents.
What happens to a file after processing
For anything that does touch our servers:
- No retention. Once the operation finishes and you've downloaded the result, the file is permanently removed. We don't archive it, mine it, or use it to train anything.
- Automatic cleanup. Files are deleted even if something goes wrong mid-process — a crash or an error doesn't leave your document sitting around. Periodic cleanup jobs make sure nothing orphaned remains.
- Isolation. While being processed, files live in isolated, per-session storage that other users and processes can't reach.
How your data is encrypted
- In transit: everything between your browser and our servers travels over TLS 1.2+ with 256-bit encryption.
- At rest: sensitive stored data (like cloud-synced passwords) is encrypted with AES-256-GCM, using per-user keys kept separately from the data they protect.
- Account passwords: hashed with bcrypt — we never store plain-text passwords.
Do you have to create an account?
No. The core tools are free to use without signing up, and the browser-based ones never upload your file regardless of whether you're logged in. An account adds optional conveniences (saved files, workflows, team sharing), and those features are access-controlled so only you — or the team members you choose — can reach your data.
How payments are handled
If you upgrade to a paid plan, Blackpdf never sees your card details. Payment processing is handled entirely by Paddle as our Merchant of Record, in a PCI DSS-compliant environment. We don't receive, process, or store credit card numbers, CVV codes, or banking information.
Common questions
Are my files used to train AI or sold to anyone?
No. We don't retain your processed files, so there's nothing to sell or train on. Files that are uploaded for server-side processing are deleted right after the operation completes.
Is it safe to upload sensitive documents like IDs or contracts?
For tools that run in your browser, the file never leaves your device at all — that's the safest case. For server-side tools, the upload is encrypted and the file is deleted immediately after processing. If a document is highly sensitive, you can also add your own protection: for example, redact information you want permanently gone, or password-protect the file before sharing it onward.
How do I know which tools upload my file and which don't?
As a rule of thumb, lightweight structural operations (merge, split, rotate, crop, reorder) tend to run in your browser, while compute-heavy ones (OCR, compression, some conversions) use server-side processing. Either way the privacy outcome is the same — no retention — but if your file is sensitive and you'd prefer it never leave your device, the browser-based tools guarantee that.
What about my account password and synced data?
Account passwords are hashed with bcrypt and never stored in plain text. Synced data such as saved passwords is encrypted at rest with AES-256-GCM using per-user keys. Sessions use secure, HTTP-only cookies with CSRF protection.
Where can I read the full details?
Our Security page lays out the complete picture — file processing, encryption, authentication, infrastructure, monitoring, and how to report a security issue — and our Privacy Policy covers what data we collect and why.
The bottom line
Blackpdf is built so that the most private path — your file never leaving your device — is the default for as many tools as possible, and the tools that do need a server delete your file the moment they're done. Add encrypted transit, encrypted storage for sensitive data, and payments handled by a PCI-compliant processor, and the honest answer to "is Blackpdf safe?" is yes — with the specifics published on our Security page so you don't have to take our word for it.