---
title: "PDF.js viewer JSON options: reference - WebTolk websites development, Joomla Extensions"
description: "Types and values apply to the 6.4.299 viewers. Numeric defaultZoomValue is still a string; theme and mode options are numbers."
url: "https://web-tolk.ru/en/dev/joomla-plugins/wt-pdf-js/documentation/viewer-options"
date: "2026-10-09T19:21:58+00:00"
language: "en-GB"
---

## Breadcrumbs

[Home](https://web-tolk.ru/en) > [Joomla extensions](https://web-tolk.ru/en/dev) > [Joomla plugins](/en/dev/joomla-plugins) > [WT PDF.js](/en/dev/joomla-plugins/wt-pdf-js) > [Documentation](/en/dev/joomla-plugins/wt-pdf-js/documentation) > PDF.js viewer JSON options: reference

# PDF.js viewer JSON options: reference

WT PDF.js - Documentation

**Category:** [Joomla plugins](https://web-tolk.ru/en/dev/joomla-plugins)

[Project](https://web-tolk.ru/en/dev/joomla-plugins/wt-pdf-js)[Versions](https://web-tolk.ru/en/dev/joomla-plugins/wt-pdf-js/versions)[Documentation](https://web-tolk.ru/en/dev/joomla-plugins/wt-pdf-js/documentation)[GitHub](https://github.com/mozilla/pdf.js)

Types and values apply to the 6.4.299 viewers.

## Option types and values for PDF.js 6.4.299

Types and values apply to the 6.4.299 viewers. Numeric defaultZoomValue is still a string; theme and mode options are numbers.

| Option | Type | Values | Purpose |
| --- | --- | --- | --- |
| `defaultZoomValue` | string | `"auto", "page-width", "page-fit", "page-height", "125"` | Initial zoom; the string "125" means 125%. |
| `viewerCssTheme` | number | `0 / 1 / 2` | 0 OS theme, 1 light, 2 dark. |
| `viewOnLoad` | number | `0 / 1` | 0 previous PDF view, 1 initial settings. |
| `sidebarViewOnLoad` | number | `-1 / 0 / 1 / 2 / 3 / 4` | -1 unspecified, 0 hidden, 1 thumbnails, 2 outline, 3 attachments, 4 layers. |
| `scrollModeOnLoad` | number | `-1 / 0 / 1 / 2 / 3` | -1 unspecified, 0 vertical, 1 horizontal, 2 wrapped, 3 page-by-page. |
| `spreadModeOnLoad` | number | `-1 / 0 / 1 / 2` | -1 unspecified, 0 no spreads, 1 odd-page spreads, 2 even-page spreads. |
| `cursorToolOnLoad` | number | `0 / 1 / 2` | 0 selection, 1 hand, 2 zoom tool. |
| `localeProperties` | object | `{"lang":"ru"}` | A locale shipped with the viewer; use en-US for English. |
| `externalLinkTarget` | number | `0 / 1 / 2 / 3 / 4` | 0 default, 1 current window, 2 new window, 3 parent, 4 top-level. Embedded viewers may replace 0 with 4. |
| `enableScripting` | boolean | `true / false` | Embedded PDF scripting. |
| `disableRange` | boolean | `false / true` | false permits Range; true disables it. |
| `disableStream` | boolean | `false / true` | true disables streaming. |
| `disableAutoFetch` | boolean | `false / true` | Use true with disableStream=true to disable automatic prefetch. |
| `enableXfa` | boolean | `true / false` | XFA support. |
| `printResolution` | number | `150` | Print DPI; higher values use more memory. |
| `maxCanvasPixels` | number | `33554432` | Canvas pixel limit; not a total memory limit. |

## JSON-LD Schema

```json
{
    "@context": "https://schema.org",
    "@type": "BreadcrumbList",
    "@id": "https://web-tolk.ru/#/schema/BreadcrumbList/17",
    "itemListElement": [
        {
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            "item": {
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                "name": "Home"
            }
        },
        {
            "@type": "ListItem",
            "position": 2,
            "item": {
                "@id": "https://web-tolk.ru/en/dev",
                "name": "Joomla extensions"
            }
        },
        {
            "@type": "ListItem",
            "position": 3,
            "item": {
                "@id": "/en/dev/joomla-plugins",
                "name": "Joomla plugins"
            }
        },
        {
            "@type": "ListItem",
            "position": 4,
            "item": {
                "@id": "/en/dev/joomla-plugins/wt-pdf-js",
                "name": "WT PDF.js"
            }
        },
        {
            "@type": "ListItem",
            "position": 5,
            "item": {
                "@id": "/en/dev/joomla-plugins/wt-pdf-js/documentation",
                "name": "Documentation"
            }
        },
        {
            "@type": "ListItem",
            "position": 6,
            "item": {
                "name": "PDF.js viewer JSON options: reference"
            }
        }
    ]
}
```

```json
{
    "@context": "https://schema.org",
    "@graph": [
        {
            "@type": "Organization",
            "@id": "https://web-tolk.ru/#/schema/Organization/base",
            "name": "WebTolk",
            "url": "https://web-tolk.ru/",
            "logo": {
                "@type": "ImageObject",
                "@id": "https://web-tolk.ru/#/schema/ImageObject/logo",
                "url": "https://web-tolk.ru/images/webtolk-1080p.jpg",
                "contentUrl": "https://web-tolk.ru/images/webtolk-1080p.jpg",
                "width": 1920,
                "height": 1080
            },
            "image": {
                "@id": "https://web-tolk.ru/#/schema/ImageObject/logo"
            },
            "sameAs": [
                "https://github.com/WebTolk",
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                "https://vk.com/web_tolk",
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                "https://tenchat.ru/sergeytolkachyov",
                "https://t.me/sergeytolkachyov",
                "https://t.me/webtolkru"
            ]
        },
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            "@id": "https://web-tolk.ru/#/schema/WebSite/base",
            "url": "https://web-tolk.ru/",
            "name": "WebTolk websites development, Joomla Extensions",
            "publisher": {
                "@id": "https://web-tolk.ru/#/schema/Organization/base"
            }
        },
        {
            "@type": "WebPage",
            "@id": "https://web-tolk.ru/#/schema/WebPage/base",
            "url": "https://web-tolk.ru/en/dev/joomla-plugins/wt-pdf-js/documentation/viewer-options",
            "name": "PDF.js viewer JSON options: reference - WebTolk websites development, Joomla Extensions",
            "description": "Types and values apply to the 6.4.299 viewers. Numeric defaultZoomValue is still a string; theme and mode options are numbers.",
            "isPartOf": {
                "@id": "https://web-tolk.ru/#/schema/WebSite/base"
            },
            "about": {
                "@id": "https://web-tolk.ru/#/schema/TechArticle/base"
            },
            "inLanguage": "en-GB",
            "breadcrumb": {
                "@id": "https://web-tolk.ru/#/schema/BreadcrumbList/17"
            }
        },
        {
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            "headline": "PDF.js viewer JSON options: reference",
            "url": "https://web-tolk.ru/en/dev/joomla-plugins/wt-pdf-js/documentation/viewer-options",
            "description": "Types and values apply to the 6.4.299 viewers.",
            "mainEntityOfPage": {
                "@type": "WebPage",
                "url": "https://web-tolk.ru/en/dev/joomla-plugins/wt-pdf-js/documentation/viewer-options"
            }
        }
    ]
}
```