Taking a known password off a PDF

Twenty-two pages that need four more added

Ines handles lettings for a small agency. On Tuesday the landlord's solicitor emails lease-14-harbour-st.pdf, 22 pages, locked with an open password he reads out to her over the phone. By Thursday she has to attach a four-page inventory at the back and send the whole lease to the new tenant.

Two things stand in the way. Merge PDF will not accept an encrypted file and says so, so the solicitor's password has to come off before anything can be added. And because the lease lists the tenant's bank details, it should not travel unprotected: it needs to go out locked again, under a password Ines picks herself.

So the cycle runs: remove, edit the open copy, read the checks, lock it again.

Removing the password in PDFGym

1. Open Unlock PDF. In the Password protection panel, the Unlock button is already pressed.
2. Choose the file or drop it onto the page. A line appears under the picker with the name, the size and, for a file behind an open password, the words "pages checked after password entry" where a page count would normally be. That wording confirms the file really is encrypted against reading.
3. Type the password into the Current password field. The Unlock PDF button stays greyed out until the field holds something.
4. Press Unlock PDF. A progress panel names each stage as it runs: reading every original page, removing the protection, writing the new PDF, opening the new file again.
5. When "Unlock complete" appears, read the verification line (explained below), then press Download unlocked PDF. Ines gets lease-14-harbour-st-unlocked.pdf; the suffix keeps it apart from the locked original.

Your file and the characters you type never leave this device. The password is also kept out of the address bar, the debug details and the site's usage data.

What the verification line actually proves

The tool does not write a file and hope for the best. It opens the new copy without any password and measures it against the original. If a single check fails, you see a message that the new PDF did not pass its page, text and security checks, and no download button is offered. For the lease, a passing result reads something like "Verified: 22 pages inspected · 100% of selectable text kept · opens without a password".

Document properties such as title, author and the original dates are carried into the copy rather than wiped.

Locking the finished file again

With the open copy, Ines merges in the inventory and names the result lease-14-harbour-st-full.pdf, now 26 pages. Then she opens Password protect PDF, chooses that file and types a new password twice, once in each field. A few rules shape what comes out:

• The password needs at least six characters, and both entries must match before the button wakes up.
• One password does both jobs. It opens the file and also serves as the owner password, and every permission (printing, copying, editing, filling in forms) is left allowed. Whoever can open the lease can do anything with it.
• Encryption is AES-128 in a PDF 1.7 file. The tool then confirms the result refuses to open without the password and opens with it.
• A file in the PDF/A archival format is refused, because encryption would break that format.
• A file that is still encrypted is refused too, with a prompt to choose Unlock instead. That is also how you change a password: unlock with the old one, protect the copy with the new one.

The download is named with a -protected suffix. Ines emails it to the tenant and sends the password by text message, so one intercepted inbox is not enough to read the lease.

Snags along the way, and the way past them

• "This PDF does not have password protection to remove." The file is not encrypted at all. If it still misbehaves in your viewer, the cause lies elsewhere, often a broken download; PDF repair can rebuild a damaged index.
• A page count shows up straight away. The pages are already readable, so what you have is a permissions lock, not an open password. Leave the field empty; the explainer on open passwords and permissions locks covers why.
• "That password did not open this PDF." A password heard over the phone is easy to mishear: zero or the letter O, a capital where you assumed lower case. Ask for it to be spelled out, and run through the typing checks in the guide to opening a locked PDF.
• Attaching the wrong file. With -unlocked and -protected versions side by side in Downloads, check the suffix before you press Send. The open one should stay on your machine.
• Losing the new password. Save it in a password manager the moment you set it. If it slips away anyway, the page on a lost PDF password covers what can still be done.

When a desktop editor or IT is the better route

The browser tool suits one file at a time with a password you hold. Some jobs ask for something else:

• A folder of forty contracts to unlock. PDFGym takes one PDF per run, so a desktop PDF editor that can process a whole folder will save an afternoon.
• You want readers to open the file but not print or copy it. PDFGym's protect step leaves every permission on, so use a desktop editor such as Adobe Acrobat Pro, which lets you set separate permissions.
• The bookmarks or fillable fields are what make the document useful. Removing the security inside a full desktop editor keeps the document structure intact instead of rebuilding it from pages.
• The file refuses to open unless a work account is signed in, or works only on a device holding a certificate. That is rights management rather than a plain password, and IT controls it.
• Your employer requires documents to stay encrypted on laptops. Keep typing the password.