Folio is a free PDF reader and editor from Forward Future, the company of AI YouTuber Matthew Berman. It reads, highlights, annotates, and signs PDFs, turns webpages and Word files into PDFs, and has an Ask AI panel that answers questions about the open document with page citations. The code is open source under the MIT license, and the first release came out on October 26, 2026.
Ask AI does not need an API key. It can use the ChatGPT or Claude subscription you already pay for: you sign in to ChatGPT inside Folio, and Claude runs through the Claude Code program on your computer. This guide installs Folio on Omarchy, adds it to the app launcher, connects Ask AI to Claude Code, and goes through reading, asking, notes, and signing, then the limits to know before you rely on it.
What you need
You need Omarchy on an x86_64 computer. Folio ships no Linux build for ARM. Omarchy uses the Super key for its shortcuts; on a PC keyboard that is the Windows key. If the Omarchy shortcuts are new to you, our list of Omarchy shortcuts to learn first covers the menu, the terminal, and closing windows. To try Omarchy without installing it, see how to try Omarchy on a Mac.
For Ask AI with Claude, you also need Claude Code signed in with your Claude subscription. Open a terminal, run claude, sign in with your Claude account, and quit it. Folio does not sign you in itself: until Claude Code is signed in, its settings say “Claude Code is installed but not signed in. Run claude in a terminal and sign in.”
Folio is not the AUR folio package
Folio has no package in the Arch repositories or the AUR. The AUR does have packages named folio and folio-bin, but both are a different app with the same name: a Markdown notes app for GNOME. Do not install them for this guide. The Snap Store also lists an unrelated “Folio PDF Reader” from another developer.
The real Folio lives at github.com/Forward-Future/folio. Its README links the downloads. For Linux there are two: an AppImage, Folio-linux-x86_64.AppImage, and a .deb file for Debian and Ubuntu. On Omarchy, use the AppImage.
Install fuse2 so the AppImage can start
An AppImage is a single file that holds the app and everything it needs. It mounts itself with FUSE when it starts, and Folio’s AppImage looks for the older FUSE 2 library, libfuse.so.2. Omarchy does not install that library by default, so without it the AppImage stops with an error about libfuse.so.2. Press super enter to open a terminal and install it from the Arch repositories:
sudo pacman -S fuse2Put the AppImage in its own folder
Keep the AppImage in a fixed place with a name that has no version number in it. Folio updates itself by replacing that file, so a launcher that points at the path keeps working after an update. Make a folder, download the release into it (about 128 MB), and mark it as a program:
mkdir -p ~/.local/share/folio
curl -L -o ~/.local/share/folio/Folio.AppImage \
https://github.com/Forward-Future/folio-releases/releases/download/v1.10.9/Folio-linux-x86_64.AppImage
chmod +x ~/.local/share/folio/Folio.AppImageThat link is version 1.10.9, the one this guide follows. The releases page lists newer versions; change the version in both places of the link to get one. You can start it now with ~/.local/share/folio/Folio.AppImage, but it is easier from the launcher.
Add Folio to the Omarchy launcher
The Omarchy launcher ( super space ) lists the apps that have a desktop entry, a small text file in ~/.local/share/applications/. An AppImage does not add one by itself. First take the icon out of the AppImage and put it where the launcher looks for icons:
cd /tmp
~/.local/share/folio/Folio.AppImage --appimage-extract 'usr/share/icons/*'
mkdir -p ~/.local/share/icons/hicolor/512x512/apps
cp squashfs-root/usr/share/icons/hicolor/512x512/apps/folio.png ~/.local/share/icons/hicolor/512x512/apps/
rm -rf squashfs-rootThen create the file ~/.local/share/applications/folio.desktop with this content (replace jim with your user name, because desktop files do not expand ~):
[Desktop Entry]
Type=Application
Name=Folio
Comment=PDF reader and editor
Exec="/home/jim/.local/share/folio/Folio.AppImage" %U
Icon=folio
Terminal=false
Categories=Office;Viewer;
MimeType=application/pdf;
StartupWMClass=folio-pdf-readerUpdate the desktop database so the launcher and the file manager pick it up:
update-desktop-database ~/.local/share/applicationsPress super space , type folio, and press enter . Folio opens in a few seconds as a native Wayland window, tiled like any other app, with its own title bar. The start screen has an Open a PDF box ( ctrl o ), links to Open from URL and Try a sample document, and the version with a Check for updates link at the bottom.
Make Folio the default PDF app (optional)
Omarchy opens PDFs in Document Viewer (Evince) by default. To open them in Folio instead, from the file manager or from xdg-open, run:
xdg-mime default folio.desktop application/pdfCheck it with xdg-mime query default application/pdf, which should print folio.desktop. To go back, run the same command with org.gnome.Evince.desktop.
Turn off automatic updates if you want a fixed version
Folio checks for new releases and updates the AppImage by itself. Version 1.10.9 came out on October 31, 2026, the 25th release in the app’s first five days. That is useful for fixes, but it also means the app can change under you, and the checks contact GitHub. To stay on one version, open the … menu at the top right, choose Settings (or press ctrl , ), and turn off Automatic updates under Updates. When it is off, Folio says it makes no background checks or downloads; you can still check by hand. About Folio in the same … menu shows the version.
Two of those releases were security fixes. The commit behind 1.10.8 says it “Fixes five reported security issues,” and the 1.10.9 release notes say it “includes all 15 security fixes.” Among the changes listed in the changelog: a link inside a PDF now opens only after an Open link? dialog that names the site, and a webpage or link that points at your own computer or local network asks first. Run 1.10.9 or newer.
Read a PDF
Press ctrl o to open a PDF. The file picker starts on Recent; click Documents or another folder to find your file. Folio remembers the last document, page, and zoom, and opens it again the next time you start the app. Opening a second file replaces the first; there are no tabs.
Folio is built for the keyboard, and ? lists every shortcut. f turns on focus mode, which shows only the page ( esc leaves it), and 2 shows two pages side by side. ctrl f searches the document, shows the number of matches, and lists the matching pages with a snippet and a count for each. To go to a page, click the page number in the bottom bar, press ctrl a , type a number, and press enter .
Night reading, a switch in Settings, dims white pages to dark grey for reading in the dark. Photos in a paper keep their colors, but diagrams drawn as vector graphics dim with the page, so on many papers it works like a dark mode for the whole page. Folio’s own light and dark themes are a separate setting.
Connect Ask AI to Claude Code
Folio looks for the claude program in ~/.local/bin and then in each folder on your PATH. On Omarchy, apps started from the launcher get the mise shims where Omarchy’s claude lives, so Folio finds it there. Open Settings and find the Claude section. Once Claude Code is signed in, Check again reports that Claude Code “is signed in with your Claude subscription.”
Out of the box, Ask AI uses ChatGPT. To make Claude the default, change Default provider to Claude in the same settings. The choice stays after a restart.
Ask AI about a PDF
Click the sparkle icon at the right end of the toolbar. The Ask AI panel opens on the right, with ChatGPT and Claude tabs, three starter questions (Summarize this document, What are the key takeaways?, What questions does this leave open?), and a box that says “Ask about this document…”. Under it, a menu picks the model (the default, Sonnet, Opus, or Haiku), and a line confirms “Using your Claude subscription via Claude Code”. Ask AI has no keyboard shortcut.
For an example we used the vLLM paper, a 16-page study of how to serve large language models with less GPU memory. We asked “What does vLLM do when GPU memory runs out? Keep it short.” The answer started in about two seconds and was done in about seven. It said vLLM preempts requests and either swaps their data to CPU memory or recomputes it later, with a citation to page 8 for the method and page 13 for the trade-off. Citations show as small orange chips. Click one, such as (p. 13), and Folio jumps to the top of that page; nothing on the page is highlighted. A citation that covers several pages, written as plain text like “(pp. 2, 4)”, is not a link.
Two habits make the answers easier to use:
- Ask for a short answer. Add “Keep it short” or “in three bullets” to the question. Without it, a question like “How much faster is vLLM than earlier serving systems, and why?” brought back about two screens of headings and bullets.
- Ask for no tables. Folio does not draw Markdown tables, so a table in an answer shows as raw lines of
|characters. Ask for “two or three sentences, no table” when a question invites a comparison.
Math in an answer shows as formatted equations once the answer finishes. While it streams, you see the raw LaTeX for a moment.
The example paper is “Efficient Memory Management for Large Language Model Serving with PagedAttention” by Woosuk Kwon, Zhuohan Li, Siyuan Zhuang, Ying Sheng, Lianmin Zheng, Cody Hao Yu, Joseph E. Gonzalez, Hao Zhang, and Ion Stoica (arXiv 2309.06180), licensed under CC BY 4.0.
Ask about a selected passage
Select some text, and a small popup appears with five highlight colors, Ask AI, a copy button, and a note field. To select a whole sentence cleanly, double-click its first word, then hold shift and click after its last word. Click Ask AI, and the passage goes above the input as a quote with its page number, such as “p. 5: …”.
In the vLLM paper we selected the sentence on page 5 that compares vLLM’s memory manager to virtual memory in an operating system, and asked “Explain this analogy in plain terms.” The answer took about 12 seconds and cited pages 5 through 8. It also included a table, which showed as raw lines of | characters.
When you ask a question, Folio runs claude -p in an empty temporary folder, with tools, MCP servers, and your Claude Code settings turned off, so the model works only with what Folio sends it. Folio sends the file name, the text it extracted from the PDF (up to about 400,000 characters), and any passage you selected. Since 1.10.9, it marks that text as quoted data and tells the model to ignore instructions inside it, which guards against a PDF that hides commands for the AI. The questions count against your Claude plan’s usage like any other Claude Code session.
The document text leaves your computer: it goes to Anthropic (or to OpenAI if you use the ChatGPT option). Do not ask about a PDF you would not paste into a chat with that provider.
Highlight, take notes, and copy them as Markdown
Select text, then click one of the colors in the popup to highlight it. To add a note, click the Add a note… field in the popup (or press n ), type the note, and press enter ; Folio saves a yellow highlight with the note. Click the field before you type: letters typed straight after a selection go to Folio’s keyboard shortcuts, and the start of the note gets lost.
The Notes tab in the sidebar lists every highlight with its page and note, plus a box for notes about the whole document. Notes save automatically on your computer. Copy all puts them on the clipboard as Markdown: a heading with the document name, each highlight as a quote with its page number, and the note under it. On Omarchy it reaches the normal clipboard, so you can paste it into a terminal editor with ctrl shift v or into Obsidian.
Sign a form with a signature image
Open the form and click Sign in the toolbar. Folio places a signature as an image, from your webcam (Use camera) or from a photo (Upload photo, PNG, JPG, or WebP). After you pick the photo, drag a box around the signature to cut off the paper edges, set the Ink sensitivity slider so the background drops out, and click Use this signature.
In the second step, Folio removes the background and suggests a spot. It looks for signature labels on the page: on a loan form with a borrower line, the Placement menu offered “Borrower signature (suggested)”. Leave Remember this signature off unless you want Folio to keep it. Nothing goes on the page until you click Approve and add signature, and ctrl z undoes it. For a date, press t for the text tool, click the date line, type, and click Done.
When you are done, press ctrl s (or Save a copy in the … menu) and pick a name. The signature and the text are saved as standard PDF annotations, so the saved copy shows them in Document Viewer too. Folio says the saved copy also includes your highlights and notes.
Open a webpage or a Word file as a PDF
Press ctrl shift o to open Open from URL, type or paste a web address, and press enter . Folio turns the page into a PDF that keeps the site’s look, and you can highlight it and ask AI about it like any other PDF. One of our Omarchy guides came out as a seven-page PDF in about 11 seconds, titled with the page’s title, but its embedded YouTube video printed as a grey box with a play button. A page without a video, such as our guide to starting a new Linux install with Fedora, avoids that. Pasting or dropping a link anywhere in Folio fills in the same dialog instead of opening the page.
Folio also opens Word files. Press ctrl o and pick a .docx file, and Folio converts it in a few seconds and saves the PDF next to the original with the same name, such as Report.pdf beside Report.docx. If that PDF already exists, the next conversion saves Report (2).pdf.
Limits to know
Folio reads text that is already in the PDF. It has no OCR (text recognition), so a scanned page stays a picture: search does not find its words, and Ask AI cannot read it.
A signature in Folio is an image stamp, not a digital certificate. That is fine for a form you print or email, but not for a document that must carry a verified digital signature.
Folio cannot edit the text on a page, and it cannot merge PDFs, reorder pages, or delete them. A PDF can be up to 300 MiB and 10,000 pages.
Remove Folio
Delete the AppImage folder, the icon, and the launcher entry, then update the desktop database:
rm -rf ~/.local/share/folio
rm ~/.local/share/icons/hicolor/512x512/apps/folio.png
rm ~/.local/share/applications/folio.desktop
update-desktop-database ~/.local/share/applicationsIf you made Folio the default PDF app, set Document Viewer back with xdg-mime as shown above. Folio keeps its settings, recent files, notes, and Ask AI chats in ~/.config/Folio; delete that folder too if you want them gone. To remove fuse2, run sudo pacman -Rns fuse2, unless another AppImage needs it.
Newer versions may look different
Folio’s first release came out on October 26, 2026, and new versions come out often. This guide follows Folio 1.10.9 on a release candidate of Omarchy 4.5. Menus, shortcuts, and Ask AI options may differ in your version. The Folio README covers the current release.
Where to go next
For other AI tools on Omarchy, see our guides to the Goose AI agent, Herdr for running coding agents side by side, and five Omarchy plugins that bring AI to your desktop. For more apps to add to a fresh install, see the Flea file manager and the new apps in Omarchy 4.5. If you are new to Omarchy, start with what Omarchy is.
