Topic
Clean a PDF Before You Share It
By Happy Turtle Tech ยท Published
A PDF that looks finished can still carry things its pages do not show: the author and software in its properties, comments and form answers, text that was only covered by a box, parts of a page that were cropped out of view but not out of the file, and images far larger than they need to be. Each of these is a different problem with a different fix, so this page puts the steps in the order that works.
Every tool linked here runs in your browser and the file is never uploaded. Each one also says what it leaves behind, because no single tool cleans everything.
1. Look before you change anything
Start by seeing what is there. Remove Hidden Data lists what the file carries before it removes anything, in groups such as document properties, attached files, scripts and comments. The Metadata tool shows every property field, including custom ones a program added without telling you.
The five-minute checklist walks the same ground by hand, and is worth reading once so you know what you are looking for.
2. Remove the properties and hidden data
Remove Hidden Data clears the document properties and their XMP copy, attached files, scripts and comments, and prunes them so they are gone from the saved file, not just unlinked from it. The Metadata tool does a narrower job: it edits or clears the property fields and can strip camera and location data from the photos inside the file.
Neither changes what the pages show. Metadata on its own is not a sanitiser: it leaves comments, bookmarks, form values and attachments alone, and says so.
3. Do not trust a crop to remove anything
Cropping a page, and the Fill mode in Resize, change what is visible. They do not delete what was trimmed away: the whole original page is still in the file for anyone who looks. If something was cropped out because it should not be seen, crop is the wrong tool; use Redact.
4. Hide what must not be read
A black box drawn over text, or white text on a white page, leaves the words in the file, where a search or a copy will find them. Redact works differently: each page you mark is rendered to a picture with the black baked into the same pixels, the page is rebuilt from that picture, and the old page is pruned out of the saved file. The text on a redacted page is gone, and so is the ability to search it.
Redact also looks for the same words in bookmarks and comments elsewhere in the file. Pages you did not mark keep their text. A redacted file is usually larger, because a page that was text is now a picture.
5. Lock in comments and form answers, or delete them
Flatten draws form answers and comments into the page, so they look the same in every viewer and can no longer be edited. That is a way to fix them, not a way to hide them: what is drawn is still on the page for everyone to read.
If a comment should not be seen at all, delete it instead. Remove Hidden Data lists comments and removes them. Flatten keeps sticky notes as notes and never draws a pending redaction mark, because a drawn mark would look redacted while the text stayed in the file.
6. Make it a size people can send
Compress has three levels. Lossless re-packs the file and drops objects nothing refers to any more, without changing any image. Balanced and Smallest also recompress the JPEG images in the file, which is lossy, and the tool says so before you start.
If a file is large because of its images, only the two lossy levels will move it much. The guides explain how to tell what is making your file big before you pick one.
7. Check the file you will actually send
Run Remove Hidden Data once more on the finished file: it should list nothing you meant to remove. If you also changed words, Compare shows which words differ between the original and the new version, so you can see that an edit did not change something you did not intend. It compares text only, so a changed picture is not reported.
The order matters for the last step, not the others: whatever you run last should be followed by a look at the result. Keep the original file, and send the copy you cleaned.