Launching Prezl from a slide deck

The most awkward moment in a "live coding" talk is the hand-off: you're on a slide, you alt-tab to your editor, you hunt for the right window, the audience watches you fumble. Prezl can be launched from a hyperlink in your slide deck instead — click the link, Prezl opens at exactly the screen you want, in fullscreen, ready to present. When you're done with the code section, one button hands focus back to the deck.

This page covers how to set it up. The full URL grammar lives in the prezl:// URL scheme reference.

At a glance

1. Open the project you want to link to in Prezl.
2. In the status bar (bottom-right), enable the prezl:// handler — see Enabling the link handler.
3. Click the share icon to copy a link to the current screen, or alt-click / right-click for options including a saveable shortcut file.
4. Paste the link as a hyperlink in your slide tool. Click it during the talk to launch Prezl.
5. Click the slideshow icon (top-right of Prezl) — or press Shift+Esc — to hand focus back to your deck.

Enabling the link handler

For Windows the prezl:// URL scheme has to be registered with the OS before slide-deck links work. The registration writes a single key under HKCU\Software\Classes\prezl — per-user, no admin prompt, no UAC. macOS and Linux equivalents work the same way through their respective mechanisms.

Installed builds register automatically during install — nothing to do.

Portable builds ship without touching the registry by design, so the status bar shows a small toggle icon that lets you opt in. Click it once to register; the icon flips to a check, and the link handler points at the currently-running exe.

Dev builds are treated like portable: the toggle is visible whenever the protocol isn't registered, so you can flip it on for local testing.

Re-registering after moving a portable exe

The registered command embeds the absolute path of the exe at the moment you register. If you move the portable exe to another folder, the link points at the old path and silently fails. Click the toggle once after moving — the registration self-heals against the new path.

Copying a link

The share icon next to the toggle is the primary action.

• Click — copies a link to the current screen with sensible defaults (fullscreen=1, hideOnExit=1). A short toast confirms.
• Alt-click or right-click — opens an options popover. Pick a different target (whole project, current screen, or any specific screen by id), toggle fullscreen / hide-on-exit, then Copy link.

If you click the share icon while the protocol isn't registered, the copy is refused — you'd just be putting a non-functional URL on the clipboard. The toast tells you to enable links first.

Saving a shortcut file

The popover also has a Save shortcut button that writes a clickable shortcut file containing the URL. Useful when your slide tool doesn't honour custom URL schemes — see tool-specific notes below. The format follows the host OS:

OS	Extension	Format
Windows	.url	Internet Shortcut (INI-like)
macOS	.webloc	Apple property list (XML)
Linux	.desktop	Desktop entry

Drop the resulting file next to your deck and hyperlink the slide to the file, not the URL. Double-clicking the file resolves through the registered handler and launches Prezl.

Tool-specific notes

PowerPoint

• In slideshow mode (F5), hyperlinks use ShellExecute and custom schemes work fine. Paste the prezl:// URL directly into Insert → Hyperlink → Address.
• In edit mode, clicked hyperlinks sometimes route through the default browser instead. If you're testing without entering slideshow, use a .url shortcut file instead.

Keynote (macOS)

prezl:// URLs work directly in slideshow mode. Insert → Add Link → Webpage, paste the URL. The .webloc workaround is rarely needed.

WPS Office

WPS funnels every hyperlink through its own browser launcher rather than the OS handler, so a raw prezl:// URL always opens in your browser instead of Prezl. Use a .url shortcut file instead: hyperlink the slide to the file, not the URL. Same trick on macOS WPS with .webloc.

Google Slides / browser-based decks

Browsers will surface a one-time "This site is trying to open prezl://" prompt the first time you click. Allow it, and subsequent clicks launch Prezl directly.

Back to the slide deck

When the deep-link sets hideOnExit=1 (the default for the share-icon copy), Prezl shows a small slideshow icon in the top bar next to the Run button. Click it — or press Shift+Esc — to hand focus back.

Behaviour is platform-aware:

• Windows / Linux — minimizes Prezl. The slideshow window behind it gets focus from the OS Z-order, so you can advance immediately with the same remote.
• macOS — hides the Prezl app via NSApp hide:. This jumps back to the previous Space, which matters if Keynote is in fullscreen presenter mode on its own Space.

The button only appears when Prezl was launched with hideOnExit=1, so manually-opened projects don't show it.

Removing the handler

In portable mode, click the registered toggle (the check icon) again. The HKCU key is deleted; clicking any prezl:// link will behave as if Prezl were never installed. You can re-register at any time.

For installed builds, uninstall removes the registration along with everything else.