Open source · Apache-2.0 · Early preview
OpenPresent is an open-source presentation editor for PowerPoint
files. Open a .pptx in your browser or on your desktop,
edit its text, shapes and slides, present it full screen, and export
PDF or PNG. Your file never leaves your machine.
No sign-up, nothing uploaded Web, macOS, Windows, Linux Star it on GitHub
01 What it does
A presentation editor with the ribbon and shortcuts you already know, over an engine whose first job is to keep your file intact.
Shapes, text, pictures, tables, charts, SmartArt and themes are read into one model. Anything the model does not hold yet is kept byte for byte, and what a slide uses that is not drawn yet is named, feature by feature.
A truncated archive, broken XML or a missing content-types part gets the best reading we can make, and the deck opens. Hostile content is neutralized rather than obeyed; only a file with nothing readable in it is refused, naming why.
Click into a text box and type, with bold, italic, underline and undo. Move, resize, rotate and delete shapes; add slides, text boxes, shapes and pictures; change the theme and slide size.
Full screen from the start (F5) or the current slide (Shift+F5), with PowerPoint's keys. Presenter View shows the next slide, your notes and a timer.
Save gives back a .pptx: parts you did not touch come back byte for byte, and an edit patches only what changed. Export a PDF with real, searchable text, or a slide as a 1920-pixel PNG.
The same editor in a native window for macOS, Windows and Linux. Open a deck from the Open panel, or double-click a .pptx; no network needed. The desktop builds are early, unsigned previews.
The engine, the editor and the desktop shell are on GitHub. unsafe is forbidden, every parser is bounded and fuzzed, and coverage of the format is measured row by row.
02 Private by design
The engine is compiled to WebAssembly and runs inside your browser, or inside the desktop app. There is no server to send a deck to: opening, drawing, editing and exporting all happen on your machine.
No upload, no account, no telemetry. Macros are never run, and links inside a deck are never fetched.
The editor
PowerPoint's tabs, groups and shortcuts, with every command it has present. What this build cannot do yet is shown disabled, with the reason in its tooltip, rather than faked.
03 Real renders, not mock-ups
Each picture is a slide of a real deck, drawn by OpenPresent's renderer when this site was built. The slide gallery shows every slide of every deck beside LibreOffice's rendering of the same file, so you can judge the difference yourself.
The slides at the top come from these three decks. The decks are unmodified and keep their own licences; the full list is in fixtures/real. The reference beside them in the gallery is LibreOffice, not PowerPoint: until our output has been checked against PowerPoint itself, nothing here claims to match it.
04 Shipping now
A list of what the editor does now, not a roadmap. It is an early preview: what is still to come is under Honest status below.
.pptx, .pptm, .ppsx, .ppsm, .potx, .potm.pptx, patching only what changedNot yet. Co-editing, autosave, animations in the slide show, editing tables and charts, and comments. The ribbon already shows those commands, disabled, so you can see where each will be.
05 Where it fits
Most ways of opening a deck ask you to install a suite or to upload the file to someone's server. OpenPresent does neither, and it is honest about being younger than both.
Kinds of tool, not products. OpenPresent is an early preview: it has fewer features than a mature suite today, and its output has not yet been checked against PowerPoint.
06 Self-hosted
The editor is static files: HTML, JavaScript, CSS and one WebAssembly engine. There is no server component, because a deck is opened and drawn in the visitor's own browser and never sent anywhere. Any web server, or any static host, will do.
# build the engine into the editor's folder
$ wasm-pack build crates/casual-slide-wasm --release \
--target web --out-dir ../../webapp/pkg
# then serve webapp/ from any web server
$ python3 -m http.server -d webapp 8080Nothing to run, patch or scale beyond serving files.
No document leaves the browser, nothing phones home, no licence check.
The page carries its own Content Security Policy; the guide lists what a header must allow.
07 Honest status
The file engine came first: reading, modelling and writing a deck without losing anything. Now it ships in thin slices you can use, each deepened in later passes.
08 Questions
Yes. It is open source under the Apache-2.0 licence: free to use, to change and to host yourself, with no account and no licence check.
No. The engine runs as WebAssembly inside your browser, or inside the desktop app. The deck is read from the file you pick and never sent to a server, and the site loads no trackers and no third-party scripts or fonts.
.pptx, .pptm, .ppsx, .ppsm, .potx and .potm: the Office Open XML formats PowerPoint has saved since 2007. The older binary .ppt format is not read.
We do not claim that. Our renders are compared with LibreOffice's in the public slide gallery, and some features are not drawn yet; each slide names what it leaves out. Before any release our output will be checked in PowerPoint itself.
Saving a deck you have not edited gives back the same bytes. When you edit, only the parts you changed are rewritten, node by node; everything else, including what OpenPresent does not model yet, is kept as it was.
Macros are never run. A .pptm opens, and its macro project is kept in the file untouched, so saving does not strip it.
Yes, with the desktop app for macOS, Windows and Linux. Today the builds are early, unsigned previews made by our CI; the download page explains the one-time step each system needs.
Try your own decks, and when one opens wrongly, open an issue with the file if you can share it. A star on GitHub helps others find the project.
No sign-up, no upload, no install. Bring a .pptx, or try our sample, then edit it, present it and export it.