PDF Decrypter Pro Reports Wrong File Size After Decryption
After running PDF Decrypter Pro on a protected document, you might notice the resulting file is either noticeably smaller, marginally larger, or simply shows a different number than what your file manager reports in the Properties panel. This is a common point of confusion for Australian users who routinely handle contracts, government forms, and university coursework in PDF format, particularly when those documents are routed through shared drives in Sydney, Melbourne, or Brisbane offices. Because the application works entirely on your local machine, the file you see is the file you actually have, yet operating systems sometimes display stale information or calculate size differently depending on how the document was reassembled.
The key is recognising when a size difference is harmless and when it points to a real problem with the decryption. A few kilobytes here or there usually reflects internal housekeeping, not corruption. A difference of many megabytes, or a file that refuses to open, suggests something went wrong during the process. The guidance below walks through what causes each scenario, what to check first, and how to bring the reported size back in line with the actual content on both Windows and macOS.
Why Decrypted PDFs Rarely Match the Source Byte-for-Byte
PDF files are not single static blobs. They are containers holding text streams, embedded fonts, raster images, form-field definitions, signature objects, and an information dictionary that records author, creation date, and software version. When PDF Decrypter Pro removes the owner password and rewrites the document without restrictions, it may normalise some of these objects, drop orphaned references, or strip encryption metadata that no longer applies. The result is a freshly serialised PDF that can differ from the original by a small margin.
The differences are usually clustered around a handful of predictable areas:
| Area affected | Typical size impact | Why it happens |
|---|---|---|
| XMP metadata block | -1 to -15 KB | Encryption tags and revision history removed |
| Cross-reference table | ±2 KB | Rebuilt after object reordering |
| Embedded font subsets | -5 to -200 KB | Unused glyphs pruned during rewrite |
| Form field appearances | +1 to +50 KB | New default appearances generated |
| Object stream compression | Variable | Modern filters often compress better than older tools |
None of these changes affect what you can do with the file. They simply reflect the cost of removing the encryption wrapper. A 12-page report that drops from 4.2 MB to 4.1 MB has almost certainly been processed correctly. A 12-page report that drops to 800 KB has probably lost images.
Common Causes of a Mismatched Size in File Explorer or Finder
Operating systems cache directory listings to keep browsing fast. On a Windows machine joined to an Active Directory domain, which is common in Brisbane legal firms and Perth mining offices, the cache can lag by several seconds. If you copied the output file while the decryption was still writing, the file manager may show a partial size until you press F5 or right-click and choose Refresh.
Another frequent culprit is shadow copies and the Windows Volume Shadow Copy service. When a previous version of the file exists in the shadow store, the size reported under Properties can pull from the snapshot rather than the live file. macOS users on APFS volumes can hit a similar issue when Time Machine holds an older index. In both cases, the actual decrypted file on disk is correct; only the displayed value is wrong.
Cloud sync clients add another layer. If the output folder lives inside OneDrive, Dropbox, iCloud Drive, or the Australian-focused providers used by some accounting firms, the sync daemon may briefly report the on-server size, which can differ from the local copy due to compression during upload. Disabling the sync client momentarily or pausing its sync will usually force the local size to display properly.
Quick Checks Before Changing Any Decryption Settings
Before assuming the application has produced a faulty file, run through a short verification routine. Open a terminal, Command Prompt, or PowerShell window and compute a SHA-256 hash of both the encrypted source and the decrypted output. If the application shows a checksum in its log, compare it. A matching hash on the source confirms the original downloaded cleanly, while a stable output hash across two separate runs confirms the decryption is deterministic.
Then check whether the document opens correctly in Adobe Acrobat Reader, Foxit, or your browser. If the decrypted file renders every page, fonts are intact, and form fields respond, the content is fine regardless of what the size column says. If pages are blank, fonts appear as boxes, or images are missing, the file has genuinely lost data and you should re-run the decryption from the original source rather than trying to repair the output.
It also helps to compare the file size shown by your operating system with the size reported inside the PDF itself. Open the document in Acrobat, choose Document Properties, and look at the File Size field. That figure is read directly from the PDF dictionary and is almost always accurate. When it disagrees wildly with what Windows or macOS reports, you are looking at a display issue rather than a content issue, which is far easier to resolve.
Resolving the Discrepancy on Windows
For Windows 10 and Windows 11 users, the fastest fix is to clear the thumbnail and metadata cache. Open File Explorer, right-click the decrypted PDF, choose Properties, and uncheck Read-only if it is set. Click OK, then right-click the parent folder, choose Properties, and run the Disk Cleanup tool with the Thumbnails and System error memory dump options selected. Restarting the application that produced the file also forces Windows to discard any locked handles that might be holding a stale size.
If you store decrypted documents on a network share, mapped drive, or a Synology NAS common in Adelaide architecture studios, the size may show the SMB transfer buffer rather than the actual file. Disconnect and remap the drive, or copy the file to a local folder such as C:\Temp and inspect it there. Australian SMB networks often run over the NBN with variable latency, which can amplify the lag between a write completing and the share reporting the correct size.
When the problem persists, verify that no security product is intercepting writes. Antivirus suites and firewalls and security tools can briefly hold a file open while scanning, which makes Windows report a pre-scan size. Whitelist the PDF Decrypter Pro installation folder and its output directory, then run the decryption again and compare the result.
Handling the Same Issue on macOS
macOS calculates file size using logical block counts on APFS volumes, and the Finder can lag when a file has been recently modified. Click anywhere else on the desktop, then click back on the output file and choose Get Info from the File menu. The size shown under More Info is recalculated on demand and is usually correct even when the list view is stale. Switching the Finder view to as List, pressing Command-1, and toggling Calculate All Sizes off and on will force a fresh count.
If the size shown in Get Info is wrong, run First Aid on the container from Disk Utility, which is built into macOS Sonoma and Sequoia. A damaged APFS catalog can cause the kernel to return incorrect extents, and First Aid rebuilds that catalog without affecting the file contents. For users on older HFS+ drives, Disk Utility's Repair Disk Permissions can produce similar results, although that option is no longer present in current macOS versions.
For documents routed through iCloud Drive or stored in a Dropbox folder synced via the Mac file provider extensions, sign out of the sync service, restart the Mac, and reopen the file directly from the local cache. Once the cached copy reports the correct size, sign back into the sync client. macOS users in creative agencies across Melbourne and Sydney often keep very large PDFs in shared Creative Cloud Libraries, and the sync handshake can confuse Finder size reporting for several minutes after a write.
When to Weigh Local Decryption Against Online Alternatives
Plenty of free websites promise to remove PDF restrictions, and they are tempting because they require no installation. They also upload your document to a remote server, which is rarely acceptable when the file contains client-confidential material covered by the Australian Privacy Act or the Notifiable Data Breaches scheme. Local processing keeps the document on your machine, which matters for legal, medical, and accounting workflows regulated by AHPRA, the ATO, or state-based health records rules.
If you are curious about how the two approaches stack up across security, privacy, and file integrity, the online unlocker comparison breaks the differences down in detail. The short version is that any size mismatch you see after running PDF Decrypter Pro locally is a reporting quirk, not a privacy trade-off, whereas using an online unlocker introduces both a reporting quirk and a confidentiality risk you cannot fully audit.
Re-run PDF Decrypter Pro on the original encrypted source, this time writing the output to a freshly created folder on your local desktop rather than a synced or shared location, then open the output directly from that folder and confirm in the Properties or Get Info panel that the document opens and prints as expected.