@tumblerjs/slides

Read and edit PowerPoint .pptx files without a UI framework.

bun add @tumblerjs/slides

Open a presentation

import { openPresentationArtifact } from "@tumblerjs/slides";

const bytes = new Uint8Array(await file.arrayBuffer());
const artifact = openPresentationArtifact(bytes);
const { slides, width, height } = artifact.document;

Slides are in presentation order. Each slide exposes its objects, notes, and diagnostics. Check object capabilities before enabling an editing control. Geometry uses CSS pixels at 96 DPI; saved transforms use native OOXML units.

Apply edits with undo and redo

import { openPresentationEditingSession } from "@tumblerjs/slides";

const session = openPresentationEditingSession(bytes);
const slide = session.artifact.document.slides[0];
const object = slide?.objects.find(object => object.movable);
if (slide && object) {
  session.updateObject({
    slideId: slide.id,
    objectKey: object.key,
    x: object.transform.x + 16,
    y: object.transform.y,
    width: object.transform.width,
    height: object.transform.height,
  });
  session.undo();
  session.redo();
}
const output = session.artifact.bytes();

updateObject changes position, dimensions, or rotation in clockwise degrees. Use editText for text ranges, formatText for text formatting, and styleShape for solid fill and outline changes. Table text commands accept a zero-based cell: { row, column } address. Edit merged cells through their anchor cell.

A session records each command as an undoable revision. Read session.artifact after a command and pass its document back to your renderer. canUndo, canRedo, and dirty expose history state.

Use the Svelte editor

Import PresentationSlideView, PresentationSlideRail, and PresentationFormattingToolbar from @tumblerjs/svelte/slides. The view emits edit callbacks; your application applies them to the session. The rail provides thumbnail navigation through a bindable index.

See the PowerPoint guide for complete viewer, navigation, editing, and download examples.

Save

Call session.artifact.bytes() when downloading or saving. Accessing artifact.document.package also materializes the ZIP, so avoid doing either after every keystroke or drag. Edits reparse the changed slide and reuse unchanged scenes, images, and decoded fonts. Undo history shares unchanged package data.

No-op export returns the original bytes. Changed slides retain unrelated XML and package parts, including supported Office extension metadata.

Compatibility

Slide-local objects can remain editable with inherited geometry or inside transformed groups. Shared master/layout objects, fields, signed packages, SmartArt cached drawings, and unknown alternate representations remain restricted. Table row/column operations and full Office layout and animation fidelity are not supported.

Use the compatibility guide for feature coverage, and the implementation notes for preservation rules and validation commands.

See THIRD-PARTY-NOTICES.md for font and image decoder notices.