# Zoom

Zoom in steps or through presets, with the toolbar, the keyboard or Ctrl/⌘ + wheel, between limits you choose.

## Basics

The zoom buttons change the scale in 5% steps between 25% and 500%; the label shows the rounded percentage.

**Demo: Default zoom controls**

```tsx
import { PdfViewer } from '@kingtech/react-pdf-viewer';

export default function Demo() {
  return <PdfViewer source="/samples/letter-3pages.pdf" />;
}
```

At 100% a page is shown at its true size (one PDF point per CSS pixel). While at the default scale, a page wider than the viewer is shrunk to fit; once zoomed, it keeps its size and the document area scrolls. <kbd>+</kbd>, <kbd>-</kbd> and <kbd>0</kbd> zoom from the keyboard.

### Presets

`zoomLevels` replaces the fixed step with a ladder of presets. `zoomReset` turns the percentage into a button that returns to `defaultScale`.

**Demo: Zoom presets with a reset button**

```tsx
import { PdfViewer } from '@kingtech/react-pdf-viewer';

const ZOOM_LEVELS = [0.5, 0.75, 1, 1.5, 2, 3];

export default function Demo() {
  return (
    <PdfViewer
      source="/samples/letter-3pages.pdf"
      zoomLevels={ZOOM_LEVELS}
      minScale={0.5}
      maxScale={3}
      zoomReset
    />
  );
}
```

### Wheel and pinch

`wheelZoom` zooms with <kbd>Ctrl</kbd>/<kbd>⌘</kbd> + mouse wheel and trackpad pinch, anchored at the pointer. A plain wheel still scrolls the page.

**Demo: Ctrl/⌘ + wheel zoom**

```tsx
import { PdfViewer } from '@kingtech/react-pdf-viewer';

export default function Demo() {
  // Hold Ctrl (⌘ on macOS) and scroll, or pinch on a trackpad, over the page.
  return <PdfViewer source="/samples/letter-3pages.pdf" wheelZoom zoomReset />;
}
```

## Controlled zoom

`scale` and `onScaleChange` put the zoom level in your state, for example to remember it per user. Values outside `[minScale, maxScale]` are clamped.

```tsx
const [scale, setScale] = useState(1.25);

<PdfViewer source={url} scale={scale} onScaleChange={setScale} />;
```

## Customization

Change the step with `scaleStep`, the wording with `labels`, and the look with CSS variables.

**Demo: 10% steps, custom labels and larger buttons**

```tsx
import { PdfViewer, type PdfViewerLabels } from '@kingtech/react-pdf-viewer';
import type { CSSProperties } from 'react';

const labels: Partial<PdfViewerLabels> = {
  zoomLevel: (percent) => `${percent} %`,
  zoomIn: 'Enlarge',
  zoomOut: 'Reduce',
};

const style = {
  '--rpv-toolbar-bg': '#1e293b',
  '--rpv-label-font-size': '13px',
  '--rpv-button-size': '38px',
} as CSSProperties;

export default function Demo() {
  return (
    <PdfViewer source="/samples/letter-3pages.pdf" scaleStep={0.1} labels={labels} style={style} />
  );
}
```

See the [customization guide](https://react-pdf-viewer-chi.vercel.app/react-pdf-viewer/customization/) and the full list of [CSS variables](https://react-pdf-viewer-chi.vercel.app/react-pdf-viewer/api/css-variables/).

## Advanced / escape hatch

`setScale(scale)`, `zoomIn()`, `zoomOut()` and `resetZoom()` on the [imperative API](https://react-pdf-viewer-chi.vercel.app/react-pdf-viewer/imperative-api/) zoom from your own controls; `canZoomIn` and `canZoomOut` tell you when to disable them. To fit the page to the viewer instead of choosing a percentage, see [Fit modes](https://react-pdf-viewer-chi.vercel.app/react-pdf-viewer/fit-modes/).

## Limitations

- **Very high zoom is capped by the canvas budget.** Above `maxCanvasPixels` (16,777,216 pixels per page by default) the page is rendered at a lower resolution and scaled up, so it looks softer. Workaround: raise `maxCanvasPixels` on desktop-only apps, or lower `maxScale`. See [Rendering](https://react-pdf-viewer-chi.vercel.app/react-pdf-viewer/rendering/).
- **Browser zoom is separate.** Ctrl/⌘ + wheel zooms the page only when `wheelZoom` is on and the pointer is over the document; elsewhere the browser zooms the whole page as usual.

## API

- [PdfViewerProps](https://react-pdf-viewer-chi.vercel.app/react-pdf-viewer/api/pdf-viewer-props.md)

---

## PdfViewerProps reference

Props for `PdfViewer`. Every piece of state supports the value / defaultValue / onChange trio.

### Used by

- [Page navigation](https://react-pdf-viewer-chi.vercel.app/react-pdf-viewer/page-navigation.md)
- [Zoom](https://react-pdf-viewer-chi.vercel.app/react-pdf-viewer/zoom.md)
- [Rotation](https://react-pdf-viewer-chi.vercel.app/react-pdf-viewer/rotation.md)
- [Download](https://react-pdf-viewer-chi.vercel.app/react-pdf-viewer/download.md)
- [Print](https://react-pdf-viewer-chi.vercel.app/react-pdf-viewer/print.md)
- [Fit modes](https://react-pdf-viewer-chi.vercel.app/react-pdf-viewer/fit-modes.md)
- [Fullscreen](https://react-pdf-viewer-chi.vercel.app/react-pdf-viewer/fullscreen.md)
- [Continuous layout](https://react-pdf-viewer-chi.vercel.app/react-pdf-viewer/continuous-layout.md)
- [Thumbnails](https://react-pdf-viewer-chi.vercel.app/react-pdf-viewer/thumbnails.md)
- [Loading states](https://react-pdf-viewer-chi.vercel.app/react-pdf-viewer/loading-states.md)
- [Page number input](https://react-pdf-viewer-chi.vercel.app/react-pdf-viewer/page-number-input.md)
- [Links](https://react-pdf-viewer-chi.vercel.app/react-pdf-viewer/links.md)
- [Text layer](https://react-pdf-viewer-chi.vercel.app/react-pdf-viewer/text-layer.md)
- [Search](https://react-pdf-viewer-chi.vercel.app/react-pdf-viewer/search.md)
- [Password protection](https://react-pdf-viewer-chi.vercel.app/react-pdf-viewer/password-protection.md)
- [Rendering](https://react-pdf-viewer-chi.vercel.app/react-pdf-viewer/rendering.md)

### Import

```ts
import type { PdfViewerProps } from '@kingtech/react-pdf-viewer';
```

### Properties

| Name | Type | Default | Required | Description |
| --- | --- | --- | --- | --- |
| `source` | `PdfSource \| null` | — | Yes | The document: a URL string or `URL`, or `ArrayBuffer` / `Uint8Array` / `Blob` / `File`. `null`, `undefined` and `''` show the empty state. |
| `fileName` | `string` | `derived from the source` | No | Download file name. Default: a `File`’s name, the URL’s last `.pdf` segment, else `document.pdf`. |
| `page` | `number` | — | No | Controlled 1-based page. Out-of-range values are clamped and reported through `onPageChange`. |
| `defaultPage` | `number` | `1` | No | Initial page while uncontrolled, and the page every new document opens on. |
| `onPageChange` | `(page: number) => void` | — | No | Called whenever the page changes, controlled or not. |
| `scale` | `number` | — | No | Controlled scale: `1` = 100%, one PDF point per CSS pixel. |
| `defaultScale` | `number` | `1` | No | Initial scale while uncontrolled; also the reset-zoom target and the scale at which fitting applies. |
| `onScaleChange` | `(scale: number) => void` | — | No | Called whenever the scale changes. |
| `rotation` | `Rotation` | — | No | Controlled clockwise rotation, added to each page’s intrinsic rotation. |
| `defaultRotation` | `Rotation` | `0` | No | Initial rotation while uncontrolled. |
| `onRotationChange` | `(rotation: Rotation) => void` | — | No | Called whenever the rotation changes. |
| `fullscreen` | `boolean` | — | No | Controlled fullscreen state. Passing it selects `fullscreenMode="controlled"` unless a mode is set. |
| `defaultFullscreen` | `boolean` | `false` | No | Initial fullscreen state while uncontrolled. |
| `onFullscreenChange` | `(fullscreen: boolean) => void` | — | No | Called whenever fullscreen is entered or left. |
| `fullscreenMode` | `FullscreenMode` | `'controlled' when fullscreen is passed, else 'native'` | No | `controlled`: layout only, the parent presents fullscreen (e.g. in its own dialog). `native`: the browser Fullscreen API on the viewer root, falling back to `overlay`. `overlay`: a fixed full-viewport layer with a focus trap; `Esc` closes it. |
| `minScale` | `number` | `0.25` | No | Zoom floor (25%). |
| `maxScale` | `number` | `5` | No | Zoom ceiling (500%). |
| `scaleStep` | `number` | `0.05` | No | Increment of the zoom buttons and the `+` / `-` keys. |
| `zoomLevels` | `readonly number[]` | — | No | Preset ladder, e.g. `[0.5, 1, 1.5, 2, 4]`: the zoom buttons step between presets instead of by `scaleStep`. |
| `fitWidthAtDefaultScale` | `boolean` | `true` | No | At the default scale, shrink the page to the available width. |
| `fitMode` | `'page' \| 'none' \| 'width'` | `'none'` | No | At the default scale, fill the width (`width`) or fit the whole page (`page`). Zooming away shows the page at true size. |
| `password` | `string` | — | No | Password for encrypted documents. Changing it reloads the document. |
| `pdfjsOptions` | `PdfJsDocumentOptions` | — | No | Per-instance `getDocument` overrides such as `cMapUrl`, `standardFontDataUrl` or `verbosity`. Source-related options are managed by the viewer. |
| `toolbar` | `boolean \| ToolbarConfig` | `true` | No | `false` hides the toolbar; an object sets `position`, `actions` and `hiddenWhenCompact`. |
| `compactBreakpoint` | `number` | `960` | No | Viewport width (px) below which the compact layout applies: less padding, and `hiddenWhenCompact` actions hidden outside fullscreen. |
| `keyboardShortcuts` | `boolean` | `true` | No | Keyboard shortcuts while focus is inside the viewer. |
| `printMode` | `'render' \| 'open-url'` | `'render'` | No | `render` prints through a hidden iframe, with progress and Cancel; `open-url` opens the PDF in a new tab. |
| `maxCanvasPixels` | `number` | `16777216` | No | Canvas pixel budget per page (4096 × 4096). Above it, resolution degrades gracefully instead of failing. |
| `labels` | `Partial<PdfViewerLabels>` | `English (defaultLabels)` | No | Overrides for any visible string or accessible name. Keep the object stable (e.g. at module scope). |
| `locale` | `string` | `the browser locale` | No | BCP 47 locale for number formatting, e.g. `hu-HU`. |
| `layout` | `'single' \| 'continuous'` | `'single'` | No | One page at a time or vertical scrolling through all pages. Only the visible pages ±1 are rendered; the page indicator follows the scroll position. |
| `textLayer` | `boolean` | `false` | No | Selectable, copyable text that assistive technology can read. |
| `annotationLayer` | `boolean` | `false` | No | Clickable links: internal links navigate, external links open in a new tab with `rel="noopener noreferrer"`. |
| `pageInput` | `boolean` | `false` | No | Editable page number in the toolbar. |
| `zoomReset` | `boolean` | `false` | No | The zoom label becomes a button that resets zoom. |
| `wheelZoom` | `boolean` | `false` | No | `Ctrl` / `⌘` + wheel and trackpad pinch zoom, anchored at the pointer. |
| `passwordPrompt` | `boolean` | `false` | No | Ask for the password of encrypted documents instead of reporting `PASSWORD_REQUIRED`. |
| `renderPasswordPrompt` | `(context: { incorrect: boolean; submit: (password: string) => void }) => ReactNode` | — | No | Replaces the built-in password form (with `passwordPrompt`). |
| `thumbnails` | `boolean` | `false` | No | Lazily rendered page thumbnails sidebar, hidden in compact, non-fullscreen mode. |
| `search` | `boolean` | `false` | No | Find bar with highlighting (implies `textLayer`). `Ctrl` / `⌘` + `F` focuses it, `Enter` / `Shift` + `Enter` step through matches, `Esc` clears. |
| `renderLoading` | `() => ReactNode` | — | No | Replaces the loading view. |
| `renderError` | `(error: PdfViewerError, actions: { retry: () => void }) => ReactNode` | — | No | Replaces the document and page error views. |
| `renderToolbar` | `(api: PdfViewerApi) => ReactNode` | — | No | Replaces the toolbar. Render `&lt;PdfToolbar api={api} /&gt;` inside to reuse parts. |
| `renderEmpty` | `() => ReactNode` | — | No | Replaces the view shown without a source. |
| `onDocumentLoad` | `(info: { numPages: number; fingerprint: string }) => void` | — | No | A document finished loading. |
| `onPageRender` | `(info: PageRenderInfo) => void` | — | No | A page render completed. |
| `onError` | `(error: PdfViewerError) => void` | — | No | Every failure except aborted loads, canceled renders and HTTP errors handled by `onHttpError`. |
| `onDownload` | `(context: { fileName: string; data: Uint8Array }) => false \| void` | — | No | Before saving; `data` holds the already-loaded bytes. Return `false` to handle the download yourself. |
| `onPrint` | `() => false \| void` | — | No | Before printing. Return `false` to handle printing yourself. |
| `className` | `string` | — | No | Added to the root (`.rpv-root`). `rpv-theme-dark` and `rpv-theme-auto` select the dark presets. |
| `style` | `CSSProperties` | — | No | Inline styles on the root, e.g. CSS variables. |
| `id` | `string` | — | No | Id of the root element. |
| `aria-label` | `string` | `labels.viewer` | No | Accessible name of the viewer region. |
| `requestInit` | `RequestInit` | — | No | Extra `fetch` options for URL sources: headers, `credentials`, `mode`, … |
| `fetcher` | `(url: string, init: RequestInit) => Promise<Response>` | — | No | Replaces `fetch` entirely, e.g. with an authenticated HTTP client. |
| `onHttpError` | `(response: Response) => boolean \| void \| Promise<boolean \| void>` | — | No | Called for non-2xx responses. Return `true` when handled (e.g. after redirecting to sign-in): the viewer shows its empty state and does not call `onError`. |
| `getHttpErrorMessage` | `(response: Response) => Promise<string>` | — | No | Builds the `HTTP_ERROR` message. Return `undefined` for the default: an RFC 7807 `detail`, then `title`, then a JSON string body, then `Failed to fetch PDF: {status} {statusText}`. |

### Source

[packages/react-pdf-viewer/src/types.ts](https://github.com/kiralygyula92/react-pdf-viewer/blob/main/packages/react-pdf-viewer/src/types.ts#L190)