universal_document_viewer 0.1.1

Open and read PDF, Word (.docx), Excel (.xlsx), CSV, PowerPoint (.pptx) and text documents in Flutter, with its own document engines.

universal_document_viewer

Open and read documents in Flutter: PDF, Word (.docx), Excel (.xlsx), CSV, PowerPoint (.pptx) and plain text. The document engines are part of the package (PDF runs on PDFium; Word, spreadsheets and slides are read by Dart code written for this package), so there is no other document plugin to add.

Use one widget, DocumentViewer.file(path), that picks the right reader for the file type, or use the controller and view for each format when you want your own app bar, search UI or saving.

Features

PDF (pdf.dart)

• Continuous (vertical) or horizontal page layout.
• Pinch, double-tap and mouse-wheel zoom; zoom in/out steps and fit-width from the controller.
• Pages are built only near the viewport, with a low-resolution image per page sharpened by tiles when zoomed in.
• Password-protected PDFs, through a password callback.
• Search across all pages with highlights, and a check for scanned PDFs without a text layer.
• Links: web links open outside the app (http, https, mailto only); links to pages jump.

Word (docx.dart)

• Continuous layout reflowed to the screen, or print layout with measured pages, per-page headers and footers and live page numbers.
• Paragraph and character styles, lists, tables with merged cells, images, links and bookmarks, footnotes and endnotes.
• Parsed in a background isolate; search with highlights; scroll position restore.

Spreadsheets (sheets.dart)

• Excel .xlsx and CSV.
• A lazy 2D grid: only on-screen cells are built.
• The file's column widths and row heights, hidden rows, columns and sheets, frozen panes, merged cells, text formatting and number formats.
• Several sheets, search, zoom, and cell links (web links and links to other cells).
• Select a row or column to see its Count, Sum and Average.

PowerPoint (slides.dart)

• .pptx slides shown as titles, paragraphs, tables and pictures, one slide at a time, with a navigation bar and search.

Text (text.dart)

• .txt and Markdown (.md, .markdown) shown as plain text, UTF-8 with a Latin-1 fallback.
• Rejects binary files; search with highlights.

All formats

• File type detection from the extension, path or MIME type (DocumentFormat).
• Office files are checked before parsing (ZipSafetyGuard): damaged ZIPs, path traversal and oversized ("zip bomb") contents are refused.
• Reading positions as plain JSON-safe maps, and typed load errors.

Legacy binary .doc, .xls and .ppt files are not supported.

Platforms

Android, iOS, macOS, Windows and Linux. Web is not supported yet.

How it compares

Most Flutter document packages read one format, show files through a web view or a vendor engine, or hand the file to another app. universal_document_viewer reads six formats inside your app with engines that ship in the package.

Package	Formats	How it shows files	Platforms	Licence
universal_document_viewer	PDF, DOCX, XLSX, CSV, PPTX, text	Its own engines: PDFium for PDF, Dart readers for Office files and text	Android, iOS, macOS, Windows, Linux	MIT
pdfrx	PDF	PDFium; also edits and combines PDFs	Android, iOS, macOS, Windows, Linux, web	MIT
syncfusion_flutter_pdfviewer	PDF	Syncfusion's PDF library	Android, iOS, macOS, Windows, Linux, web	Syncfusion licence (commercial, with a community licence)
pdfx	PDF	Pages rendered as images	Android, iOS, macOS, Windows, web	MIT
flutter_pdfview	PDF	The platform's native PDF view	Android, iOS	MIT
docx_viewer	DOCX, DOC	Flutter widgets	Android, iOS, macOS, Windows, Linux, web	MIT
microsoft_viewer	DOCX, PPTX, XLSX	Flutter widgets	Android, iOS, macOS, Windows, Linux, web	MIT
power_file_view, flutter_filereader	Office, PDF, text	Tencent X5 on Android, WKWebView on iOS	Android, iOS	MIT / not stated
open_filex	Any	Opens the file in another app	Android, iOS	BSD-3-Clause

Formats, platforms and licences are as listed on pub.dev in October 2026.

What sets it apart:

• One package for PDF and Office files. DocumentViewer.file(path) opens any of the six formats; there is no PDF package plus a Word package plus a spreadsheet package to wire together.
• One contract across formats. Every reader has a controller with search, a saved reading position as a JSON-safe map, and typed load errors, and DocumentThumbnails draws a first-page (or resumed-page) thumbnail for every format.
• Everything stays in your app. No web view, no third-party browser engine and no other app. Files are read on the device; nothing is uploaded.
• Spreadsheets read like the original. Column widths, frozen panes, merged cells, number formats, borders and conditional formatting, in a lazy grid that builds only the cells on screen.
• Safe with untrusted files. Office files are checked before parsing: damaged ZIPs, path traversal and zip bombs are refused.
• MIT licensed, with the third-party pieces (PDFium) listed in NOTICE.md.

When another package fits better:

• You need web: pdfrx and syncfusion_flutter_pdfviewer support it; this package doesn't yet.
• You need to edit PDFs, fill forms or annotate: pdfrx and Syncfusion do that; this package reads only.
• You need legacy .doc, .xls or .ppt files: they aren't supported here.

Installation

flutter pub add universal_document_viewer

To use the latest code from GitHub instead:

dependencies:
  universal_document_viewer:
    git:
      url: https://github.com/macdipu/universal_document_viewer.git

It needs Dart 3.11.4 or later and Flutter 3.41 or later.

PDFium

The PDF engine needs the PDFium native library. You don't add it yourself: the package's build hook (hook/build.dart) downloads a prebuilt PDFium for the target platform from bblanchon/pdfium-binaries at build time. The release is pinned and every archive is checked against a pinned SHA-256 before it is used. The first build for each platform therefore needs network access.

Quick start

import 'package:universal_document_viewer/universal_document_viewer.dart';

DocumentViewer.file(
  path,
  initialPosition: savedPosition, // reopen where the reader left off
  onPositionChanged: (position) => save(path, position),
  errorBuilder: (context, error) => Center(child: Text('Cannot open: ${error.name}')),
)

DocumentViewer picks the reader by file type: PDF, Word, Excel (with sheet tabs), CSV, PowerPoint (with slide navigation) or text. It shows a short English message when a file can't be opened, unless you pass errorBuilder. Pass passwordProvider to ask for the password of an encrypted PDF; without one it shows passwordRequired.

See example/ for a runnable app.

Per-format readers

Every controller is a plain ChangeNotifier (no state-management package). Each takes an initialPosition, reports changes through onPositionChanged, and has search, clearSearch, nextMatch and previousMatch. Dispose controllers you create.

Import	Controller	View
package:universal_document_viewer/pdf.dart	PdfDocumentController	PdfDocumentView
package:universal_document_viewer/docx.dart	WordDocumentController	WordDocumentView
package:universal_document_viewer/sheets.dart	SpreadsheetController	SheetGrid
package:universal_document_viewer/slides.dart	SlideDeckController	SlideDeckView, SlideNavigationBar
package:universal_document_viewer/text.dart	TextDocumentController	TextDocumentView

PDF

The view opens the file itself; the controller drives it.

import 'package:universal_document_viewer/pdf.dart';

final controller = PdfDocumentController(onPositionChanged: save);

PdfDocumentView(
  path: path,
  controller: controller,
  passwordProvider: () => askForPassword(), // Future<String?>; null gives up
);

controller.zoomIn();
controller.zoomOut();
controller.fitWidth();
controller.toggleViewMode(); // continuous <-> horizontal
controller.jumpToPage(10);
controller.search('invoice'); // results in controller.searchController

Word

import 'package:universal_document_viewer/docx.dart';

final controller = WordDocumentController(initialPosition: saved, onPositionChanged: save);
await controller.load(await File(path).readAsBytes());

if (controller.error == null) {
  WordDocumentView(controller: controller);
}

controller.toggleViewMode(); // continuous <-> print layout (WordViewMode)
controller.search('agreement'); // matches in controller.searchController
controller.nextMatch();

package:universal_document_viewer/word.dart has the Word engine on its own: DocxReader.read(bytes) returns a WordDocument model.

Spreadsheets

import 'package:universal_document_viewer/sheets.dart';

final controller = SpreadsheetController(onPositionChanged: save);
await controller.loadXlsx(bytes); // or loadCsv(bytes)

SheetGrid(controller: controller);

controller.switchSheet(1); // sheet names in controller.sheetNames
controller.zoomIn();

PowerPoint

import 'package:universal_document_viewer/slides.dart';

final controller = SlideDeckController(onPositionChanged: save);
await controller.load(bytes);

Column(children: [
  Expanded(child: SlideDeckView(controller: controller)),
  SlideNavigationBar(controller: controller),
]);

Text

import 'package:universal_document_viewer/text.dart';

final controller = TextDocumentController(onPositionChanged: save);
controller.load(bytes); // synchronous

TextDocumentView(controller: controller, fontSize: 14, wrap: true);

Reading positions

A position is a ReadingPosition, a plain Map<String, Object?> of JSON-safe values. Store it as-is (for example with jsonEncode) and pass it back as initialPosition to reopen at the same place. The keys are in PositionKeys:

Reader	Keys
PDF	pageNumber, pageCount, viewMode
Word	scrollOffset, viewMode, paragraph (the paragraph at the top)
Spreadsheets	sheetIndex, verticalOffset, horizontalOffset, row, column, freezeTopRow (the reader froze the header row)
PowerPoint	slideIndex, slideCount
Text	scrollOffset, line (the line at the top)

Positions are reported as the reader moves; debouncing the saves is up to you.

Errors

The Word, spreadsheet, PowerPoint and text controllers expose error as a DocumentLoadError:

• tooLarge: the file, or a ZIP's declared contents, is bigger than the reader will load.
• corrupted: damaged or truncated, or an encrypted Office file.
• passwordRequired: an encrypted PDF without (or with a wrong) password.
• unsupported: not a format the kit reads.

The wording is yours. PdfDocumentController.error holds the PDF engine's exception (PdfOpenException or PdfEngineException), and DocumentViewer maps every failure to a DocumentLoadError for its errorBuilder: an encrypted PDF it couldn't unlock is passwordRequired, any other PDF failure corrupted.

Office files are checked before they're parsed: a file over ZipSafetyGuard.maxFileBytes is not read at all, and ZipSafetyGuard refuses a ZIP whose declared contents are too large. A part that inflates past the size its ZIP declares is refused as it's read.

Thumbnails

DocumentThumbnails.render draws a file's first page as PNG bytes of a given width (height follows the page's shape). Every format is covered:

• PDF: page 1.
• Word: page 1 in print layout.
• PowerPoint: slide 1.
• Spreadsheets and CSV: the top-left cells of the first visible sheet.
• Text: the first lines.

final Uint8List? png = await DocumentThumbnails.render('/path/to/report.docx', width: 160);

Pass a saved position to draw where reading left off instead:

• PDF: the saved page.
• Word: the print-layout page holding the paragraph that was at the top. Past 1,000 blocks into the body, it shows a page starting at that paragraph instead.
• PowerPoint: the saved slide.
• Spreadsheets and CSV: the saved sheet, from the saved top-left cell.
• Text: the lines from the one that was at the top.

final Uint8List? resumed = await DocumentThumbnails.render(path, width: 160, position: savedPosition);

A position that doesn't fit the file, or one saved without these keys, gives the first page.

It returns null rather than throwing for unsupported, damaged, encrypted or too-large files. Caching is up to you; the OpenReader app keeps them on disk.

Other libraries in this package

• universal_document_viewer.dart: DocumentViewer, DocumentThumbnails, DocumentFormat, ReadingPosition, PositionKeys, DocumentLoadError, ZipSafetyGuard, decodeTextBytes.
• word.dart: the Word engine (DocxReader, the WordDocument model).
• testing.dart: buildDocx, buildXlsx and buildPptx build small documents in memory for tests.

Related packages

universal_document_viewer is the first of a family of viewer packages. These are planned and not released yet:

• universal_image_viewer: open and view images in Flutter.
• universal_viewer: one viewer for documents and images, built on universal_document_viewer and universal_image_viewer.

Showcase: OpenReader

OpenReader is a document reader app built on universal_document_viewer and shows everything it does:

• Google Play: https://play.google.com/store/apps/details?id=com.chowdhuryelab.openreader

The package's own test app is in example/: sample documents in every format, every reader, and an on-device integration test.

Licence

universal_document_viewer is released under the MIT License.

Third-party code and the PDFium binary keep their own licences; see NOTICE.md and licenses/.