Preview on iPad not reliably saving pen inputs

b.riesel wrote:

apple preview on ipad does not reliably save pen inputs...we almost always loose pen inputs, when we close an Document, which we annotate something with the pen in Preview. Is there a workaround, to save the input for 100% in the document?

That is one of the most frustrating iPad bugs, and you are definitely not alone—Apple’s Quick Look/Markup feature (the default "Preview" engine on iPadOS) is notoriously unreliable for holding onto live Apple Pencil annotations when you close a file.

Because the default Markup view handles annotations as a temporary visual overlay before "flattening" or saving them back to the original file, it often drops changes if the file syncs to iCloud mid-edit, or if the app closes before forcing a write.

Here are the most reliable workarounds to guarantee your pen inputs are 100% saved every time.

1. The "Flatten via Share" Trick (100% Guaranteed)

Instead of tapping Done to close and save the document, force iPadOS to bake your drawings directly into the file vector structure using the Share Sheet.

1. Finish your annotations with your Apple Pencil.
2. Tap the Share button (the square with the arrow pointing up) at the top right before closing.
3. Select Print from the share menu.
4. In the print preview window, pinch outwards on the document preview with two fingers (this converts the print job into a flattened PDF file).
5. Tap the Share button again from this new preview and select Save to Files to overwrite or save your updated file.

Why this works: Converting to a print preview forces iPadOS to render every single pen stroke into the hard graphics layer of the PDF, making it mathematically impossible for the annotations to "disappear."

2. Open Files Without the Pencil First

A known trigger for lost annotations is opening a document directly by tapping it with the Apple Pencil.

• The Issue: Tapping a PDF with the pencil can trigger a "quick preview" mode rather than a full read/write state in the Files app.
• The Fix: Always tap to open the PDF using your finger. Wait half a second for the document to fully load, tap the Markup icon (the pen tip in a circle), and then start writing with your pencil.

3. Duplicate Before Annotating

If you are working with large PDFs or cloud-synced files (iCloud Drive, OneDrive, Google Drive), background auto-syncing often overwrites your active edits with the un-annotated cloud version right as you hit "Done."

1. Long-press the PDF in the Files app and select Duplicate.
2. Annotate the duplicate copy locally.
3. Once finished, tap Done. (Even if a sync glitch occurs, local duplicates hold onto memory buffers far better).

4. The Ultimate Fix: Switch to a Dedicated PDF App

If your daily workflow heavily involves annotating documents, Apple’s built-in Markup overlay is simply too risky. Switching to a free or dedicated third-party reader bypasses the built-in Preview engine completely:

• Goodnotes / Notability: Best if you are taking extensive handwritten notes over documents.
• PDF Expert / Adobe Acrobat Reader: Best if you just need to markup, highlight, or sign standard business/school PDFs reliably. They auto-save incrementally after every stroke.