Read-only · one binary · no runtime
A document viewer for PDF, EPUB, comics and images. One 9.7 MB binary, no service behind it, no cloud in front of it — a keystroke away, and gone when you close it.
Measured in CI on every push, and the page is checked against those numbers — a stale figure fails the build.
Every format goes through one Document trait. The window never learns what a file extension is.
| Format | Engine | State |
|---|---|---|
pdf | hayro — pure Rust, Apache/MIT | Tiled, zoomable |
epub | own reflow engine, spine-ordered | Selectable, searchable |
cbz cbr | zip, and RAR through the UnRAR decoder | Rendering |
| images | png jpeg gif webp bmp tiff psd | Rendering |
md txt | the same reflow engine as EPUB | Selectable, searchable |
xlsx xlsm | own reader — a zip of XML, drawn as a grid | Selectable, searchable |
docx | own reader — paragraphs and heading styles, reflowed | Selectable, searchable, approximate |
pptx | own reader — shapes carry their own coordinates | Text only |
odt ods odp | OpenDocument — the same three pipelines, another dialect | Same as the OOXML above |
| Office / ODF | — | Six formats, three pipelines, all read-only |
A viewer that grows features stops opening before you blink.
No annotation, no forms, no signing, no saving. Open, read, close.
Nothing leaves the machine. No account, no sync, no telemetry, no update check.
A format is supported when a pipeline ships with it, not when someone installs one.
The gaps are on the roadmap with their blockers, not in a footnote.
hayro renders pages but exposes no glyph-to-character mapping. EPUB, Markdown and text are selectable and searchable today.
No shaping yet, so Devanagari, Arabic and Thai come out wrong. The fix is skrifa and harfrust; the plan is written, the code is not.
It needs GTK on Linux. The right answer is a D-Bus status item, which is its own piece of work.
Prebuilt archives for Linux, Windows and macOS are on the releases page, each with a SHA-256 beside it.
# from source
cargo run --release -p feather-app -- document.pdf
# look at it without a display
feather-viewer --screenshot out.png --page 41 comic.cbr
# register with the desktop — a candidate, never the default
packaging/linux/install.shEverything is one keystroke; nothing hides in a menu.
↑ ↓ PgUp PgDn scroll
← → Home End page
+ − 1 zoom in, out, fit width
] [ next, previous tab
p · w pin a tab · close a tab
drag · c select text · copy
/ · Enter · Esc search · next hit · close
o open a document
n open in a window of its own
Ctrl Alt F summon from anywhere
Everything here is free, offline and accountless. If it earned its keep, there are a few ways to say so — pick whichever is easiest where you are.
One-off tip, no account needed.
ko-fi.com/matneo →
For outside India, or a card instead of UPI.
paypal.me/drsohilmomin →
The Amazon author store — every title, one shelf.
Amazon bookstore →
The rest of the estate, all of it offline-first.
drsamonline.github.io →
Bugs, corrections, requests.
sohilmomin2000@gmail.com →
No accounts, no tracking, nothing on this page loads from the network. A thank-you is a thank-you; nothing is gated behind it.
Scan with any UPI app. Payee: Dr. Sohil Momin.