AnsNew PDF Reader

A fast native PDF reader for people who actually work in a document: read, mark up, fill forms, export, and look up words — including Bangla — without opening a browser or a heavy office suite.

Built in Rust. Drawn with egui and wgpu. Pages come from PDFium, the same engine Chrome uses, on a tile renderer made for large files.

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Why this reader

Most “light” readers only scroll. Most “full” readers are slow, paid, or both. AnsNew sits in the middle:

• It stays quick on long documents because it draws only the tiles on screen.
• Highlights, notes, and form values are real PDF objects. Save them and they open in any other viewer.
• Click a word and get pronunciation, an offline English–Bangla meaning, and optional speech — no account, no API key.
• One window handles export, convert, and merge. Print uses the system dialog.

It is a ground-up rewrite of an earlier Electron app. The browser shell is gone. What remains is a small native program.

What makes it different

	AnsNew
Feel	Native window. Menus and toolbars stay the same size while the page zooms from 10% to 3200%.
Large files	Tile cache on a √2 zoom ladder. Fast scrolling cancels tiles you have already left.
Markup	Highlight, underline, strikeout, squiggly, rectangle, sticky note, and text box. Undo and redo.
Forms	Text fields and checkboxes you can fill on the page or in a sidebar, then save.
Learning	Offline dictionary, IPA, system text-to-speech, and a Google Translate link for the exact selection.
Scripts	Bundled fonts for Latin, Bengali, Devanagari, Arabic, Hebrew, Tamil, and Thai.
Ship it	Portable zip, two classic installers, and a signed MSIX. Double-click a PDF after install.

Radio buttons, dropdowns, and list boxes are listed and explained in the Forms panel. The PDF binding this app uses cannot write those field types, so they are marked “not fillable” instead of failing on click. Text and checkboxes round-trip through Save.

How fast it stays

The page is a grid of tiles, not one giant bitmap.

• Only tiles inside the viewport are rasterized. Zoom and scroll reuse bitmaps already in memory.
• Tiles render at the screen’s pixel density, so HiDPI stays sharp.
• PDFium runs on one background thread. The window never waits on it.
• A generation counter drops work for a view you have already scrolled past, so a fast flick does not build a queue.
• When the page is still, the app stops requesting frames.
• Export and merge run on that same engine thread, with progress and Cancel. A job that would render more than 100 megapixels is refused up front.

That is the speed model: draw what you see, throw away what you left, and keep the interface free.

Tools

Read. Continuous or single page. Fit width (default), fit page, or 10%–3200%. Rotate. Thumbnails, outline, jump to page, full-document Find. Several files in tabs. Drag and drop, or pass a path on the command line. Encrypted files get a password prompt. Seven themes. Settings persist.

Mark up. Select, Highlight, Underline, Strikeout, Squiggly, Rectangle, Note, Type. A Comments list jumps to each note, edits its text, or deletes it. Undo (Ctrl+Z) and redo (Ctrl+Y). Flatten bakes notes and field values into the page.

Fill. Every open PDF is scanned for AcroForm fields. The Forms sidebar shows name, type, value, and how many are left. Type in the field on the page or in the list. Pick the font and size for typed values, including Bengali and the other bundled scripts. Save writes them into the PDF.

Look up. With the Select tool, click a word or drag a phrase. A card inside the window shows IPA (CMU dictionary), English–Bangla senses, and a Speak button (Windows, macOS, or Linux system voice). Bangla selections look up the English headword. A link opens Google Translate on the exact text. Dictionaries load in the background (~12 MB) so startup stays light. Turn any of this off in Settings.

Export and print. File → Export (Ctrl+E): current page to PNG or JPEG, every page to images, chosen pages to a new PDF, images to a PDF, or merge several PDFs. Print (Ctrl+P) hands a temporary PDF to the system print dialog.

Files. Save and Save As write to a temp file, then rename, so a crash cannot leave a half-written PDF. Closing a dirty tab asks first.

Stack

Piece	Role
Rust 1.98.1 (edition 2024)	Language. Release builds use thin LTO and a stripped binary.
egui / eframe	Immediate-mode interface: menus, sidebars, settings, export window.
wgpu	GPU backend behind the window.
PDFium (pdfium-render)	Open, rasterize, annotate, fill, save. The only native PDF seam.
image	PNG and JPEG for export and “images to PDF”.

The code is a Cargo workspace: core (state), pdf (engine), render (tiles and hit testing), ui (widgets), app (window), search, lens (dictionary), platform (speech and URLs), and xtask (fetch, run, package). The UI sends a command, a pure reducer returns effects, and the shell does the I/O. Most of the logic is testable without a window.

Comparison

A fair snapshot of where this app sits. “Fast” here means time-to-first-page and scroll on a long PDF, not a lab benchmark.

	AnsNew	Browser viewer	SumatraPDF	Acrobat
Engine	Native Rust + PDFium	The browser’s PDF plugin	Native, very small	Full commercial suite
Long documents	Tile cache, UI stays responsive	Fine until the tab gets heavy	Excellent	Capable, heavier
Highlights and notes	Saved into the PDF	Limited or none	Mostly view	Full
Fillable forms	Text and checkbox, saved	Basic	View	Full, including choice fields
Offline word lookup + speech	Built in (English–Bangla)	No	No	No
Install size	Small native app + PDFium	Already installed	Tiny	Large
Price	Free, MIT	Free	Free	Paid
Best when	You read, mark, fill, and study	You only need a quick look	You want the smallest viewer	You live in a full PDF suite

Build and run

You need Rust 1.98.1 (pinned in rust-toolchain.toml) and a network connection the first time, so the build can fetch PDFium.

cargo xtask fetch-pdfium     # once
cargo run -p pdfreader-app

Or both in one step:

cargo xtask run

Open a file, inspect one without a window, or run tests:

cargo run -p pdfreader-app -- path/to/document.pdf
cargo xtask inspect path/to/document.pdf
python tools/generate_fixtures.py target/test-pdfs
cargo test

forms.pdf from the fixture script is the quickest way to try the Forms sidebar.

Shortcuts

Keys	Action
Ctrl+O	Open
Ctrl+S / Ctrl+Shift+S	Save / Save as
Ctrl+W	Close tab
Ctrl+F	Find
Ctrl+Z / Ctrl+Y	Undo / redo
Ctrl + / Ctrl - / Ctrl 0	Zoom in / out / 100%
Ctrl+E / Ctrl+P	Export / print
Ctrl+B	Sidebar
F11	Full screen
Esc	Leave full screen, or back to the Select tool

Menus follow the usual desktop order: File, Edit, View, Go, Settings, Help. Settings opens a preferences window (appearance, reading, language tools, form text, performance). Help holds the shortcut list and About.

Package for Windows

These tasks build a release binary, stage pdf-reader.exe, pdfium.dll, the licence texts, the three dictionaries, and fonts/, then wrap that folder. They run on Windows.

cargo xtask dist:portable   # zip — unpack and run
cargo xtask dist:nsis       # setup.exe  (needs NSIS)
cargo xtask dist:inno       # setup.exe  (needs Inno Setup)
cargo xtask dist:msix       # signed .msix
cargo xtask dist:msix -- --no-sign

Outputs land in target/dist/, named with the version from the root Cargo.toml (currently 5.0.5).

Package	What you get
Portable	One folder in a zip. Settings still go to %APPDATA%\pdf-reader.
NSIS / Inno	Installs under Program Files, Start Menu shortcut, uninstall entry. Shows up as AnsNew PDF Reader in Open with and in Default apps.
MSIX	Full-trust desktop package with a .pdf file association. Signed with a self-signed certificate carrying the Store publisher identity. Trust that cert once — certutil -user -addstore Root target\dist\pdf-reader-sign.cer — then Add-AppxPackage.

Installer tools, if you do not have them:

winget install -e --id NSIS.NSIS
winget install -e --id JRSoftware.InnoSetup

Release builds are windowed: no console on launch, and speech does not flash a terminal. The app runs on macOS and Linux too; the dist:* tasks are the Windows ship path. On other systems, cargo xtask run is the way to build and start it.

Windows will not silently replace a PDF app the user already chose. After install, pick AnsNew once under Open with → Always, or in Settings → Default apps.

Privacy

The app collects nothing: no account, no analytics, no telemetry, and no network code at all. Documents are opened, edited and saved on your own machine. The one exception is the Translate button in the word-lookup popup, which opens a Google Translate link containing the word you selected in your own browser.

The full policy is in privacy_policy.html — it is the document submitted to the Microsoft Store listing.

License

MIT — see LICENSE. Free to use, modify, and ship, including commercially, as long as the copyright and permission notice stay with the code.

PDFium is BSD-3-Clause. egui, eframe, wgpu, pdfium-render, and image are MIT or Apache-2.0.

Author

YAMiN HOSSAIN — @needyamin