Best PDF Compression Settings (A Decision Guide)
Last updated
There's no single "best" compression setting — there's only the best setting for what you're about to do with the file. The level that's perfect for emailing a receipt would ruin a document headed to a print shop. So instead of a magic number, what you need is a quick way to match the setting to the purpose.
This guide is that decision matrix. It maps the levels in the free Compress PDF tool — Low, Recommended and Strong — to the situations where each makes sense, and explains the trade-off behind every choice. The tool runs in your browser with nothing uploaded, and shows the size saving so you can confirm your pick.
Read it once and you'll stop guessing — you'll know which level to reach for the moment you see what the document is for.
Step by step
- 1
For email attachments: Recommended
The default sweet spot. It clears Gmail's 25 MB and Outlook's ~20 MB limits for most files while keeping the document comfortably readable on screen.
- 2
For upload portals with tight caps: Strong
Government and HR portals often cap at a few megabytes. Strong gets you there. Scans survive it well; check designed documents stay acceptable.
- 3
For printing or formal records: Low
When the file will be printed or kept as a quality record, use Low to preserve the most detail. Only compress at all if the file genuinely needs to be smaller.
- 4
For long-term archiving: minimal or none
Archives should favour fidelity over size. Compress lightly if at all, and keep an uncompressed master — you can always shrink a copy later, but you can't restore lost detail.
- 5
For web and screen-only viewing: Recommended to Strong
Documents that will only ever be read on a screen tolerate heavier compression. Lean toward Strong for fast-loading web downloads where print quality is irrelevant.
- 6
Confirm with the before-and-after size
Whatever you pick, the tool shows the saving. If a lighter level already meets your target, take it — there's no prize for over-compressing.
Tips
- Purpose first, setting second. Decide what happens to the file, then pick the level — not the other way around.
- Scans tolerate stronger settings than designed documents. The same Strong level that's fine for a scanned form may soften a photo-rich brochure too much.
- Every level rasterises pages and removes selectable text. If the document must stay searchable, that affects your choice as much as size does.
- Text- and vector-heavy PDFs barely shrink at any setting — there's little image data to compress, so don't expect Strong to work miracles.
- Keep an uncompressed master for anything important. Compression is one-way; the master lets you re-derive any size you need later.
Try it on your phone
The PDF Editor app makes matching setting to purpose easy on the go: compress offline, preview the result, and adjust the level before sharing. It also supports protected files and keeps everything on-device.
