Not all PDF size reductions use the same method. Re-saving document structure is different from reducing scan resolution or re-encoding photographs. The PDF Compress tool currently performs structural re-saving; it does not downsample images.
1. Identify what makes the file large
A document containing scanned page images may already have compact structure while the image data dominates its size. A text-heavy document may have a different balance of fonts, objects and metadata. File size alone cannot establish which case applies.
Inspect a copy in a PDF viewer. Is text selectable? Are pages scans? Are there attachments, annotations, forms or signatures you need to preserve? Those answers help determine whether a simple re-save is appropriate.
2. Understand the options we actually provide
- Compact object streams changes how eligible PDF structural objects are stored. It does not change photograph quality.
- Clear common document information clears selected fields such as author and title. It is not comprehensive metadata removal or redaction.
The tool compares the resulting byte length with the original. If it is not smaller, no download starts and the status explains that outcome. Repeatedly clicking with the same file and settings is unlikely to create a different compression method.
3. Check the output rather than just the success message
Open the downloaded PDF. Compare page count, text, page appearance, forms, annotations and features you rely on. Keep the original. A re-save can affect signatures or specialized document behavior even if ordinary pages appear unchanged.
The regression suite reopens a synthetic 25-page PDF after re-saving and checks page count. That is evidence for a bounded case, not a guarantee for every PDF, browser or document feature.
4. Choose the next action based on the problem
If only a subset of pages is needed, consider the PDF merge/split tool and check that removing pages is acceptable. If scans need downsampling, use an application that explicitly supports that operation; do not assume this structural tool implements it.
Encrypted, damaged or unusually large files may fail to load or exceed the browser's available memory. A local-processing tool still has device limits. Do not remove restrictions or alter a document unless you are entitled to do so.
5. Do not confuse smaller with sanitized
Removing a title field does not remove names printed on pages, embedded image data, attachments, comments or every metadata stream. Drawing a rectangle over text is also not necessarily redaction. This tool is for size experimentation, not a claim that a document is safe to disclose.
Selected files are processed locally. The surrounding page can load dependencies and other services as explained in the privacy policy.