解密 PDF：在线免费移除密码（2026 年完整指南）

Yes. The unlock tool requires the current password. Without the correct password, the file stays locked. This is by design: PDF encryption is meant to be secure, and a tool that bypassed passwords would defeat the entire security model. iHatePDF Unlock PDF is for users who legitimately own or have access to a protected PDF and want to remove the password for convenience, editing, or further processing.

Yes. A free account unlocks up to 3 protected PDFs in a single batch (up to 80 MB each, 120 MB total); without signing in you can unlock one file up to 80 MB. If several files share the same password, turn on the master password to enter it once for the whole batch instead of file by file. When you unlock more than one file the results are returned together as a ZIP. Only password-protected PDFs are accepted - the tool detects encryption and skips anything that isn't locked.

No. iHatePDF cannot recover or guess PDF passwords. PDF encryption (especially AES-256) is computationally infeasible to brute-force with current technology. If you have lost the password to your own file, recovery is not possible. Going forward, store all important passwords in a password manager (1Password, Bitwarden, LastPass, Apple Keychain, Google Password Manager) the moment you set them.

No. The content, formatting, images, fonts, layout, hyperlinks, form fields, annotations, bookmarks, and signatures are all preserved exactly. The only change is that the AES encryption layer is removed. The file opens normally in any PDF reader without a password prompt. Page count, file structure, and embedded resources stay identical.

Yes. Click the cloud icon during upload and authenticate once with your cloud provider. After that, browse cloud folders and select protected PDFs directly. The unlocked PDF can be saved back to the same cloud location with one click. The password is used during the unlock job and discarded immediately after.

Yes. Files upload over HTTPS, process on our secure servers, return to you as unlocked PDFs, and the original protected files delete automatically at the end of your session. Passwords you enter are used to decrypt the file during the job and discarded immediately, never stored, logged, or transmitted to third parties. No human review, no AI training, no third-party sharing. GDPR-compliant.

Yes. Works in any modern mobile browser (Safari on iPhone, Chrome on Android, Firefox, Edge, Samsung Internet). Upload protected PDFs from your phone storage or cloud, enter the password, and download the unlocked version. Useful when you receive a protected PDF on your phone and need to forward an unprotected version to someone who does not need the security layer.

Modern AES encryption (AES-128 and AES-256, used by PDFs from Adobe Acrobat 7 and later, plus most online tools) is fully supported. Legacy RC4 encryption (older PDFs from before 2009) also works. Both standard PDF password types are supported: user password (required to open the document) and owner password (controls printing, copying, editing permissions).

Because the encryption is secure (it cannot be bypassed without the password) but workflow needs sometimes require removing the password from files you legitimately own. Common reasons: you protected your own PDF and no longer need that protection, the file is for internal use and the password is just friction, you need to edit or merge the file and most tools cannot modify encrypted PDFs, or the recipient is constantly asking you to resend without protection. Unlock PDF respects the security model: password required, no bypass.

Yes. After unlocking and editing or processing the file, use Protect PDF to apply a new password (or the same one). This is the standard workflow for modifying a protected PDF: unlock with the current password, make changes, re-protect with the new password. The file then has fresh encryption applied.

All Unicode characters are supported in passwords: accented letters, non-Latin scripts (Cyrillic, Chinese, Arabic, etc), special symbols, emojis. Type the password exactly as it was set. If the password was set using a particular keyboard layout, ensure your current keyboard input matches (some special characters look identical but have different Unicode codes from different keyboards).

Yes. Digital signatures stay intact after unlocking; the cryptographic validity of signatures is independent of password encryption. Form field values (filled-in inputs, checkboxes, signatures fields) are preserved exactly. Annotations and comments also remain. The unlocked PDF is functionally identical to the protected version, just without the password barrier.

No. No watermarks, no signup gate for single conversions, no daily caps. The unlocked PDF is just your original file with the encryption layer removed. iHatePDF makes money through optional Pro features, not by watermarking free tool output.