Compressing
How to Optimize a PDF for the Web
Make a PDF that loads fast in a browser — linearisation, sensible image resolution, and the structural clean-up that matters for online documents.
A PDF on a website has a different job from one attached to an email. It has to start rendering before it has finished downloading, and it has to do that on a phone connection.
Optimise a PDF
- 1Open the Optimize PDF tool and add your file.
- 2Run it — the structure is cleaned up and the file is linearised for progressive loading.
- 3Compress separately if images are still making it heavy.
What linearisation does
An ordinary PDF keeps its index at the end of the file, so a reader must download the whole thing before it can display anything. A linearised — "fast web view" — PDF puts the first page and a hint table at the front, so a browser can render page one while the rest is still arriving.
On a 30 MB report over a mobile connection, that is the difference between an instant first page and forty seconds of blank screen.
The other structural wins
- Subset fonts to the characters actually used, rather than embedding whole families.
- De-duplicate resources — the same logo stored once instead of on every page.
- Drop unused objects left behind by editing.
- Rewrite the file to discard incremental save history.
- Remove embedded attachments that do not need to be there.
Also do these
| Action | Why |
|---|---|
| Set a document title | Browsers show it in the tab; search engines use it |
| Give the file a descriptive name | The URL is a ranking and usability signal |
| Check the metadata | Author and producer fields are published with the file |
| Serve it with gzip | Helps the text portions, though images are already compressed |
Consider whether it should be a PDF at all
PDFs on the web are worse than HTML pages for almost everything: they do not reflow on a phone, they are slower to load, they are harder for screen readers, and they rank less well. Publish as a page and offer the PDF as a download for people who want to print or file it.
Do it now
Optimize PDF
Optimize PDF for web and faster loading. It runs in this browser tab — your file is not uploaded anywhere.
Open Optimize PDFFrequently asked questions
What is fast web view?+
Another name for linearisation — the file is restructured so a browser can display page one before the download finishes.
What size should a web PDF be?+
Under 5 MB where you can manage it. Above 10 MB, most mobile visitors give up.
Does optimising change how the document looks?+
The structural clean-up does not. Reducing image resolution does, though at 150 DPI the difference on screen is not visible.
Do PDFs rank in search results?+
Yes, they are indexed. An HTML page on the same content will normally outrank them.