Folium Support

iPhone and iPad: iOS/iPadOS 17 or later. Mac: a Mac with Apple silicon, macOS 14 or later.

Text recognition (OCR) needs iOS 18 or macOS 15 or later. Searching handwritten notes needs iOS 27 or macOS 27 or later.

In the Library, tap Add (+), then choose "Import..." to pick a file from the Files app, or "Scan Documents..." to scan paper with your camera.

You can also choose Folium from the share menu in other apps, such as Mail or Files. On Mac, when you open a PDF from Finder with Folium, you can choose "Add to Library" or "Edit Original" (see below). Word and Excel files are converted to PDF when you import them (Folium Pro).

Open the document you want to keep, then drag other PDFs or images in from Finder or Files (iPad and Mac). Drop them on a page to insert them after that page, or drop them between the thumbnails in the sidebar or onto the Pages grid to insert them right there. Each image becomes one page.

You can also tap Add in Pages and choose "Insert from Files..." or "Insert from Library...".

With iCloud Drive turned on, documents are stored in the "Folium" folder in your own iCloud Drive. You can see them in the Files app and Finder, and they sync automatically across your iPhone, iPad, and Mac. With iCloud Drive off, documents are stored only on that device.

In the Library, tap Add (+) and choose "New Folder" (on Mac, you can also press ⇧⌘N). Drag documents onto a folder, or right-click a document (touch and hold on iPhone and iPad) and choose "Move to..."; you can select several documents at once. Folders are real folders inside the "Folium" folder in iCloud Drive, so the Files app and Finder show the same organization. When you delete a folder, the documents inside move up one level instead of being deleted.

Right-click (or touch and hold) a document and choose "Tags..." to add tags, create new ones, or change their colors. Tap a tag in the sidebar (on iPhone, in the row at the top) to list every document with that tag.

Yes. Library search looks at titles, and also at the text inside PDFs, scans you've run text recognition on, and the text boxes and form entries you've added. Tap a result to open the document right at that page.

The first time, each device takes a little while to go through your documents. For documents that haven't been downloaded to this device yet, the words inside become searchable after you've opened them once. To search handwritten notes, open the document and search inside it (iOS 27 or macOS 27 or later).

Use "Save to Original": Folium writes your changes back to the file you originally opened, and compares every page before it writes. You can also use "Export" to save a new copy of the PDF.

Folium keeps its own copy of the original PDF, so you can undo mistakes or go back to an earlier version in "Version History."

Yes. When you open a PDF from Finder with Folium, choose "Edit Original." The document isn't added to the Library, and your changes are saved back to that PDF automatically: a few seconds after you stop, when you switch to another window, or when you close the window. Before saving, Folium compares every page, the same as always.

If you don't want to be asked every time, check "Remember my choice and don't ask again," or pick a default under "Opening PDFs" in Settings. If the original was changed outside Folium, or it has a digital signature or redactions, Folium stops first and lets you decide how to save.

When you open a PDF this way, Folium's editing data (handwriting and markup you can still change, plus undo history) stays only on that Mac and doesn't sync to your other devices. To keep working on another device, choose "Add to Library."

Select a PDF in Finder and press ⌘I. Under "Open with," choose Folium, then click "Change All...". From then on, double-clicking a PDF in Finder opens it in Folium.

After drawing with the pen or highlighter, keep your pen on the screen and pause for a moment. Lines, arrows, circles, rectangles, and triangles snap into clean shapes. To get your hand-drawn stroke back, tap Undo once.

If you don't want this, turn off "Hold to Snap to Shape" in Settings.

No. When iCloud syncs, Folium merges the changes from both devices. If both happen to change the same part of the same page, you get an extra conflict copy of that page so you can choose which one to keep.

Open Settings (on iPhone and iPad, the gear at the top left of the Library; on Mac, "Folium > Settings..." in the menu bar) and choose "Upgrade to Folium Pro...". If you switch devices or reinstall, tap "Restore Purchases" in the same place.

With the same Apple Account, it works on iPhone, iPad, and Mac. If you use Family Sharing, your family can use it too.

No. Folium Pro is a one-time purchase: pay once and keep it, with nothing more to pay later and no automatic renewal.

See the app for current prices.

Purchases are handled by Apple. To request a refund, go to reportaproblem.apple.com and sign in with the Apple Account you used to buy.

Nothing is lost. Changes you made with Pro can still be viewed, saved to the original, and exported. You just can't make new Pro edits (like editing text again).

Folium signs following the international standard for PDF signatures (PAdES), so PDF apps that support signature validation can check them. Whether a signature counts legally depends on the certificate you use and the laws where you are. A "self-created" certificate in Folium is one you make yourself; it isn't issued by a government or a certificate authority.

Folium has no accounts and doesn't keep your data on the developer's servers. To delete documents, delete them in the Library or from the "Folium" folder in iCloud Drive. Deleting the app also deletes its data on that device.