Shift

A fast, local image viewer for people who browse folders of photos and screenshots from the keyboard.

Looking through a folder of screenshots usually means a photo manager that wants to import it into a library first, or a different built-in viewer on every operating system. Shift opens one image, or a whole folder, and steps through the folder in natural order from the keyboard. It works offline, keeps no library and never changes your files.

Status: early and deliberately small. The viewer logic is covered by unit tests that drive the real update() function: opening a file or a folder, unreadable images and empty folders, navigation, zoom, natural sort order, the status line, opening and closing Preferences, and saving and reloading the preferences file, corrupt files included. CI runs them on Linux, Windows and macOS and on the Rust 1.88 floor, with clippy and rustfmt. Drawing, most of the keyboard and mouse bindings, fullscreen and the file pickers have no automated tests. The interface ships in English and French.

Why Shift

• No import step. Photo managers keep a catalog of your pictures. Shift reads the folder as it is on disk, every time, and stores nothing about it.
• Natural order. shot-2.png comes before shot-10.png, so numbered screenshots and camera files stay in sequence.
• The same viewer everywhere. One binary per platform for Linux, Windows and macOS, with the same keys on all three.
• Keys for everything. Open, move through the folder, zoom, fit and go fullscreen without reaching for the mouse.

What it does

• Opens an image from a native file picker, or a whole folder from a native folder picker.
• Lists the other supported images in the same folder and lets you move through them.
• Fit-to-window, which shrinks large images to the window or screen and leaves small ones at their real size.
• Manual zoom, with mouse wheel zoom and a scrollable zoomed view.
• A fullscreen mode that hides the surrounding chrome.
• A status line with the position in the folder, file name, dimensions, file size and last modified time.
• Supported formats: PNG, JPEG, WebP, GIF and BMP.
• Preferences, behind the Shift button in the top-left corner: the Colony themes and accent colours, text size, high contrast, a dyslexia-friendly font, reduced motion and the interface language (English or French, or the system's). A change applies and is saved at once.

Keyboard shortcuts

Keys	Action
O	Open an image
D	Open a folder
Left / P / [	Previous image
Right / N / ]	Next image
Home / End	First / last image
+ / = / .	Zoom in
- / ,	Zoom out
0 / F	Toggle fit and manual zoom
1 / R	Reset zoom
M	Toggle fullscreen
Esc	Close Preferences

While Preferences is open, the viewer keys are off and only Esc works.

Installation

Via Colony (recommended)

Search for Shift in Colony and install it. Updates arrive through the launcher.

Direct binary download

Grab the asset for your platform from the latest release:

Platform	Asset
Linux	shift-linux
Windows	shift-windows.exe
macOS (Apple Silicon)	shift-macos
macOS (Intel)	shift-macos-x86

Each asset comes with .sig, .meta and .meta.sig files. The Code signing policy below shows how to check them.

chmod +x shift-linux && ./shift-linux

Build from source

git clone https://github.com/Project-Colony/Shift
cd Shift
cargo build --release

Requires Rust 1.88 or newer.

The binary is built as target/release/shift (shift.exe on Windows). shift --version prints the version and exits without opening a window.

Code signing policy

Every release asset is signed by the Project Colony organisation in CI, never on a developer machine. Next to each asset on the release page:

File	What it is
<asset>.sig	an ed25519 signature over the asset, made with the organisation's release key
<asset>.meta	three lines binding the asset to its file name, its sha256 and the release version
<asset>.meta.sig	an ed25519 signature over the .meta

The private key is an organisation secret, used only by the shared sign-and-publish workflow in a job that builds nothing; the jobs that compile Shift never see it. Colony checks all three files before it installs or updates Shift, and refuses a release older than the one installed. To check a download yourself with OpenSSL 3 (the same commands work for every asset):

cat > colony-release.pub <<'EOF'
-----BEGIN PUBLIC KEY-----
MCowBQYDK2VwAyEARNjg3Nn8H6/aBg1unwGjkUTcrdTxERNefVaqU8cFu0s=
-----END PUBLIC KEY-----
EOF
a=shift-linux
openssl pkeyutl -verify -pubin -inkey colony-release.pub -rawin -in "$a" -sigfile "$a.sig"
openssl pkeyutl -verify -pubin -inkey colony-release.pub -rawin -in "$a.meta" -sigfile "$a.meta.sig"
cat "$a.meta"     # version=<tag>, asset=<file name>, sha256=<digest>
sha256sum "$a"    # the digest must equal the sha256 line

How releases are built, signed and published: design/releases.md.

Privacy

Shift sends no telemetry, no analytics and no crash reports.

Data	Stored or sent	Where, and why
The image you open	read	to show it, with its size and last modified time in the status line
The folder it is in	read	listed to find the other supported images, so you can move through them
Your preferences	stored on this computer	written when you change one, read at launch, in preferences.json (paths below)
Images and folders you opened	not kept	Shift remembers no file or folder between runs

The preferences file is the only file Shift writes:

Platform	Path
Linux	~/.config/Colony/Shift/preferences/preferences.json (or under $XDG_CONFIG_HOME)
Windows	%LOCALAPPDATA%\Colony\Shift\preferences\preferences.json
macOS	~/Library/Application Support/Colony/Shift/preferences/preferences.json

The About category of Preferences shows the path in use. Delete the file to go back to the defaults.

This program will not transfer any information to other networked systems unless specifically requested by the user or the person installing or operating it. Shift has no network code at all: it connects to no server, and the preferences file never leaves your computer.

License

GPL-3.0-or-later. See LICENSE.