Annotations

People mark up a document in three modes: Annotate (highlights, notes, ink and text), Shapes and Insert (stamps, images, files and signatures). They select an annotation to move, resize or turn it, change its color, width or kind in the style panel, and undo with Ctrl/Cmd+Z. Everything they make is a standard PDF annotation, so it opens the same in Acrobat and every other PDF app.

The tools#

Each tool’s button is tool:<id>. Change what a tool draws with the annotation plugin’s tools:

{
  plugins: {
    annotation: {
      tools: [
        { id: 'highlight', defaults: { color: '#fde047', opacity: 0.4 } },
        { id: 'ink', defaults: { color: '#1d4ed8', strokeWidth: 2 } },
      ],
    },
  },
}

import { Component } from '@angular/core';
import { EpdfPdfViewer, type ViewerConfig } from '@embedpdf/viewer-angular';

const article = '/pdfs/article.pdf';

@Component({
  selector: 'demo-root',
  imports: [EpdfPdfViewer],
  template: `<epdf-pdf-viewer [src]="article" [config]="config" style="height: 100%" />`,
})
export class App {
  readonly article = article;
  readonly config: ViewerConfig = {
    plugins: {
      annotation: {
        tools: [
          { id: 'highlight', defaults: { color: '#fde047', opacity: 0.4 } },
          { id: 'ink', defaults: { color: '#1d4ed8', strokeWidth: 2 } },
        ],
      },
    },
  };
}

Try it: in Annotate, pick Highlight and select a sentence of the blog post, then Draw on the page: a pale yellow highlight and a thin blue line, the defaults above.

A tool of your own extends a built-in one, and its button goes wherever you put it:

{
  plugins: {
    annotation: {
      tools: [
        {
          id: 'approved',
          extends: 'free-text',
          defaults: { contents: 'Approved', fontColor: '#15803d' },
        },
      ],
    },
  },
  layout: (layout) => layout.add('tool:approved', { to: 'annotate', group: 'text' }),
}

Every field a tool takes, and what happens after drawing, is on Tools & defaults.

Comments#

Every annotation can carry a comment and replies. The comments panel lists every thread in page order; picking one goes to its annotation. The user’s identity is the author of what they write. In a read-only viewer, people read every thread but can’t add to it.

Fonts#

The font picker, your own fonts and text in any language are on Fonts.

Stamps#

The stamps panel has the standard stamps, such as Approved and Confidential, in the user’s language, and every stamp library people make: from an image, from selected annotations, or from a PDF they import. The libraries they make are kept in the browser across visits.

{
  plugins: {
    stamp: {
      standard: 'https://files.example.com/stamps/{locale}.pdf', // or false for none
      quick: ['standard:Approved', 'standard:Rejected'], // in the Insert toolbar
    },
  },
}

The stamp plugin’s own settings go in the same place: see Stamps.

Redaction#

In the Redact mode, people mark text or areas, check them in the redaction panel, then apply. Applying removes what’s under each mark from the file for good: the text, the images and the drawing, not just what shows. The color and label of a redacted area are settings:

{
  plugins: {
    redaction: { overlay: { fill: '#111827', text: { color: '#ffffff' } } },
  },
}

See Redaction.

Measurements#

In the Measure mode, people measure distances, perimeters and areas. A drawing’s scale comes from the PDF when it has one; otherwise they set it once with Calibrate, by drawing a line of a known length. A page with no scale uses the default:

{ plugins: { measurement: { defaultScale: 'imperial' } } }

See Measurements.

From code#

viewer.get('annotation') is the annotation plugin: list, create, change and delete annotations, and listen for changes:

const annotation = viewer.get('annotation');
 
annotation.onCreated(({ annotation: created }) => save(created));
await annotation.create(0, {
  subtype: 'square',
  rect: { x: 72, y: 72, width: 200, height: 100 },
});

Every method is on Annotations with code.

Good to know#

Saved in the PDF#

Annotations, comments and stamps are written into the file when it’s downloaded, as standard PDF annotations. To keep them in your own database instead, export and import them with the annotation plugin: see Saving annotations.

Change a mark’s kind#

The style panel’s Type turns a selected highlight into an underline, a squiggly line or a strikethrough, and a square into a circle and back. It stays the same annotation, with its comment and its replies. A strikethrough that is part of a replacement keeps its kind, and so does a locked annotation. From code it’s annotation.selection.update({ subtype }); see A style panel.

Undo#

Undo and redo cover everything people do to annotations: drawing, moving, restyling, deleting, and comments.