Compress PDF on iPhone & iPad

Open this page in Safari, tap the drop zone, and choose Browse to pick your PDF from the Files app, iCloud Drive or Google Drive. Tap Compress and then Download — the smaller file is saved back into Files, ready to attach or share.

Yes, and these compress exceptionally well. The Notes and Files scanner saves pages as high-resolution photographs, so a ten-page scan easily reaches 30 MB. Downsampling to screen resolution routinely reduces that by 85–95% while keeping the pages perfectly readable.

Compression is memory-intensive and iOS Safari limits how much memory a tab may use. Recent iPhones handle documents up to roughly 50 MB comfortably; older models may reload the tab on very large files. If that happens, close other tabs first or split the document.

Yes. The interface is fully responsive and the engine runs on iOS and Android. Bear in mind that mobile devices have less memory, so very large files (over roughly 50 MB) may be slow or fail on older phones.

Both, layered. Structural optimization — removing duplicate objects, dead revisions and metadata — is entirely lossless. Image downsampling and JPEG re-encoding are lossy, which is where the substantial savings come from. Text and vector graphics are never touched by either stage.

Yes, in two ways. Pick one of four calibrated presets for a quality-led decision, or switch to Target Size mode and enter an exact figure in KB or MB. Target mode steps through progressively stronger settings and stops at the highest quality that still fits your limit.

You can compress them, but be aware that any modification to a PDF invalidates its cryptographic signature — this is true of every compression tool, not just ours. If the signature must remain valid, do not compress the signed document.

It depends on the content. Scanned or image-heavy documents commonly shrink by 70–95%. Text-only PDFs that were already optimized may only drop 5–20%, since there is little redundant data left to remove.

Rarely, and it is usually counterproductive. The first pass already removes structural waste and downsamples images; a second pass mostly re-encodes already-degraded JPEGs, which loses more quality for negligible gain. Prefer a stronger preset on the original file instead.

Compression is one-way, but your original file is never modified — it stays exactly where it was on your device. The compressed version is written as a separate download, so you always retain the source and can simply try again with a gentler preset.