Diagrams that explain themselves
A diagram is a snapshot of an explanation someone gave once. Present mode plays it back — spotlight, notes, narration — and exports the whole thing as a video.
A diagram is usually the residue of an explanation. Someone stood at a whiteboard, drew boxes in an order, said why each one mattered, and what survived is the boxes. The order is gone. The reasons are gone. Whoever opens the file next gets the map without the walk.
Diagramium’s Present mode is an attempt to put the walk back.
Playing a diagram rather than showing it
Open a diagram and press play. It reveals itself one element at a time, in the order the author chose. A spotlight lifts the current step out of the page. A panel beside it carries that step’s note, and — where the author wrote one — a “why this matters” card that says what the box is for rather than what it is called.
It can narrate. There is a voice, subtitles, and word-by-word highlighting that follows the speech. Around 1,500 ready-made diagrams ship with the app, and the narrated explainers among them were voiced properly rather than left to a robot reading a caption.
Then it exports the whole show as a video file, which is what makes it useful to someone who was not there.
Choices that were harder than they look
The camera stays still unless standing still is worse. An animated diagram that pans and zooms every step is nauseating and hides the shape of the thing. So the view only moves when the text would otherwise be too small to read — and when it does, it moves once, keeps one scale for the whole show, and lands the subject a third of the way in rather than dead centre, so the next step is not already at the edge.
Layout belongs to the engine, not the file. Positions used to be baked at authoring time from browser-measured text. That made every diagram machine-specific: a file authored on one machine could lay out subtly wrong on another. Diagrams now carry logical grid cells and the engine solves real coordinates on load, from its own measurements, while keeping the baked positions so an older version still renders.
Your work stays in your browser. Local-first, for the reasons in the studio note on that.
Diagramium is free and at diagramium.com.