flashbang

Turn your browser's address bar into a shortcut launcher. Type !g kittens to search Google, !w dogs for Wikipedia, !gh react for GitHub — over 14,000 shortcuts (called "bangs") that take you straight to the right site, instantly. No extra tabs, no round-trips, no waiting for a page to load.

Every other bang tool loads a full page before redirecting — adding hundreds of milliseconds — or routes through an edge server adding network latency. Flashbang skips the page entirely — a Service Worker handles the redirect before your browser even starts rendering.

Try it now

Visit flashbang-dyr.pages.dev — if your browser supports OpenSearch, flashbang will appear in your search engine list automatically. Otherwise, add https://flashbang-dyr.pages.dev?q=%s as a custom search engine in your browser. Optionally, set https://flashbang-dyr.pages.dev/suggest?q=%s as the suggestion URL for address bar autocomplete. That's it.

Already using DuckDuckGo, Brave, or Kagi?

All three support bangs natively — but every query still round-trips through their servers before redirecting, adding significant network latency you can feel. Flashbang's Service Worker resolves the bang locally in ~1ms and redirects before any network request leaves your machine. You also get bang-aware search suggestions in your address bar, custom bangs, feeling lucky, and it works in any browser — not just the one your engine ships with.

Privacy

Core redirects never leave your machine — the Service Worker handles them offline with no server involved. Search suggestions are completely optional and go through our server when enabled on the hosted version. A same-site cookie stores your configured suggestion provider so the server knows which upstream to proxy — no accounts, no sessions, no personal data. There is no tracking or analytics — we don't know what you search or what bangs you use. Cloudflare Pages exposes basic request counts in its dashboard as a platform feature we did not opt into and cannot disable. It contains no query content or personally identifiable information.

If you'd rather not trust our server at all, Flashbang is fully self-hostable. Deploy to Cloudflare Pages/Railway in minutes or docker run it on any VPS — a single command gets you a fully private instance. See Setup for details.

Features

• Built for speed — Sub-1ms median redirect latency in our testing, advertised as ~1ms to be conservative. That's the overhead Flashbang adds before your browser starts loading the destination — network time to reach the target site is the same regardless of which tool you use. The Service Worker intercepts requests before they hit the network, parses the bang, and responds with a 302 — no page load, no framework, no round-trip to a server. Don't trust our numbers? Run the benchmark yourself — results vary by machine
• Private — No analytics, no tracking. All data stays on your device for the core feature - redirects
• 14,000+ bangs — Merged from DuckDuckGo, Kagi, and custom sources. Updated daily via automated CI
• Custom bangs — Add your own bangs through the settings UI. They take priority over built-ins
• Search suggestions — The only bang tool with bang-aware autocomplete in your browser's native address bar. Type !y and the browser itself suggests !yt (YouTube), !ya (Yandex), !yf (Yahoo Finance) — ranked by popularity so the most-used bangs surface first. Regular queries return web search suggestions from Google, DuckDuckGo, Bing, Brave, or a custom provider. Both are unified through a single /suggest endpoint that plugs into your browser's built-in suggestion UI
• Feeling Lucky — Prefix a query with \, or add a bare ! before or after it, to skip the results page and jump straight to the first result. Works with Google's "I'm Feeling Lucky" when that's your default engine, falls back to DuckDuckGo's \ redirect for others. Configurable per-engine or with a custom URL, or disable it entirely
• OpenSearch — Browsers auto-discover Flashbang as a search engine via /opensearch.xml, including the suggestions endpoint. The XML is dynamically generated at request time using the current origin, so it works out of the box on any self-hosted domain or localhost — no hardcoded URLs to change

Bang syntax

Flashbang supports 4 formats. All bangs are case-insensitive.

Format	Example	Result
Prefix bang	!g kittens	Google search for "kittens"
Suffix bang	kittens g!	Google search for "kittens"
Prefix, query first	kittens !g	Google search for "kittens"
Suffix, bang first	g! kittens	Google search for "kittens"

If the query is just a bang with no search term (e.g. !g), Flashbang redirects to the service's homepage.

Feeling Lucky

Skip the search results page and go directly to the first result. Three syntax options:

Format	Example	Result
Backslash	\kittens	First result for "kittens"
Trailing !	kittens !	First result for "kittens"
Leading !	! kittens	First result for "kittens"

The redirect destination depends on your lucky provider (configurable in settings):

• Default (match bang) — Uses your default search engine's native lucky feature if available (Google btnI, DuckDuckGo \), otherwise falls back to DuckDuckGo's \ redirect
• Google / DuckDuckGo / Kagi — Always use that engine's lucky redirect
• Custom — Provide your own URL template with {} as the query placeholder
• Disabled — Lucky syntax is treated as a normal search query

Setup as search engine

Note: Search suggestions and OpenSearch auto-discovery require a server endpoint since browsers don't route these requests through Service Workers — both are completely optional. Redirects always work offline once installed with no server needed. If you use the hosted version, these requests go through our Cloudflare Pages Functions. No queries are logged or stored — self-host if you'd rather keep them local too.

Use the hosted version

A public instance is available at flashbang-dyr.pages.dev. Just visit it, then add it as a custom search engine in your browser:

• Search URL: https://flashbang-dyr.pages.dev?q=%s
• Suggestion URL: https://flashbang-dyr.pages.dev/suggest?q=%s (Optional)

Nothing to build or deploy.

Deploy your own

Cloudflare Pages (recommended) — supports both redirects and suggestions out of the box:

1. Deploy the repo to Cloudflare Pages with build command bun run codegen --from-merged && bun run build and output directory dist
2. The Pages Functions automatically handle /suggest (search suggestions) and /opensearch.xml (search engine discovery with correct origin) on the edge
3. Visit the site — your browser will auto-discover it via OpenSearch
4. Or manually add a custom search engine:
   • Search URL: https://your-domain?q=%s
   • Suggestion URL: https://your-domain/suggest?q=%s

Railway — detects the Dockerfile and deploys automatically:

1. Connect your repo on Railway
2. Railway builds the Docker image and sets the PORT environment variable automatically
3. Connect domain (you can auto-generate it in settings)
4. Add a custom search engine:
   • Search URL: https://your-app.up.railway.app?q=%s
   • Suggestion URL: https://your-app.up.railway.app/suggest?q=%s

Other static hosts (Netlify, Vercel, etc.) — redirects work, but suggestions and dynamic OpenSearch require adding serverless functions for /suggest and /opensearch.xml. See functions/ for the implementations — they reuse shared modules from src/ and can be adapted to any serverless platform.

Self-host with Docker (recommended)

Run your own instance on any VPS. No dependencies to install — just Docker:

docker build -t flashbang .
docker run -p 3000:3000 flashbang

The image uses a multi-stage build — fetches bang sources, builds assets, and produces a minimal runtime image. Static assets are pre-compressed with Brotli at build time and served automatically, falling back to uncompressed for clients that don't support it. The port is configurable via the PORT environment variable (-e PORT=8080). Set it as your browser's custom search engine:

• Search URL: http://your-host:3000?q=%s
• Suggestion URL: http://your-host:3000/suggest?q=%s

Self-host without Docker

Requires Bun. Service Workers need an HTTP origin (not file://), but a local server works fine:

bun run codegen && bun run build && bun run start

bun run codegen fetches the latest bang definitions from DuckDuckGo and Kagi and generates the JavaScript bang maps. bun run build bundles, minifies, and pre-compresses all static assets with Brotli into dist/. bun run start serves the production build locally. Visit the local URL once — the Service Worker installs and redirects work offline after that. Set it as your browser's custom search engine:

• Search URL: http://localhost:3000?q=%s
• Suggestion URL: http://localhost:3000/suggest?q=%s (Optional)

To pick up new bangs, pull the latest changes and re-run bun run codegen. If you host it, the daily GitHub Actions CI does this automatically.

The settings page has a copy button that gives you the exact search URL template.

Settings

Open the settings modal from the gear icon on the home page, or type !settings in the address bar to jump there directly. Type ! on its own to quickly access the home page.

• Default bang — The bang used when no ! is in the query. Defaults to g (Google). Change it to ddg, b, or any valid bang trigger
• Feeling Lucky — Choose how lucky redirects resolve: Default (match your default bang), Google, DuckDuckGo, Custom (your own URL template with {} as query placeholder), or Disabled
• Search suggestions — Choose the source for address bar autocomplete: Default (matches your default bang), Google, DuckDuckGo, Bing, Brave, Custom (provide your own URL template with {} as query placeholder), or None
• Custom bangs — Add bangs with a trigger, name, and URL template (use {} as the query placeholder). Custom bangs override built-in ones
• Search bangs — Real-time search across all 14,000+ bangs by trigger, name, or domain
• Import/Export — Export your settings and custom bangs as JSON. Import to restore or sync across devices

All settings are stored in IndexedDB locally on your device.

How it works

When you type !gh react in the address bar, the Service Worker intercepts the request before it reaches the network. It parses the bang trigger, looks it up in the bang map (checking custom bangs first, then built-ins), and responds with a 302 redirect. If no bang is found, your default search engine is used.

See DEVELOPMENT.md for build pipeline and project structure details.

Comparison with other bang tools

	flashbang	unduck	unduckified	rebang
Redirect method	Service Worker intercept	window.location.replace	window.location.replace	Cloudflare Worker (edge) + client fallback
When redirect happens	Before page renders (Service Worker)	After page loads (HTML, CSS, JS)	After page loads (HTML, CSS, JS)	At the edge or after page loads (HTML, CSS, JS, React)
Sources	DDG + Kagi + custom	DDG	Kagi	DDG + Kagi
Analytics	None†	Plausible	None†	Plausible+Vercel Analytics+Vercel Speed Insights
Server required	No (redirects), yes (suggestions, OpenSearch)	No	No	Yes (Cloudflare Worker)
Feeling Lucky	Yes (configurable per-engine)	No	No	No
Search suggestions	Yes (bang autocomplete + configurable)	No	No	No
OpenSearch	Yes (dynamic, self-host friendly)	No	Yes	Yes
Custom bangs	Yes (IndexedDB faster)	No	Yes (localStorage)	Yes (localStorage)
Build tool	Bun	Vite	Vite	Vite
Bang data for redirects	~867 KB (trigger→URL only)	2.7 MB (full metadata)	1.5 MB (full metadata)	~200 KB inline + 1.5 MB lazy-loaded
Parsed on	SW thread (once, persists in memory)	Main thread (every page load)	Main thread (every page load)	Main thread (every page load) or edge worker
License	AGPL-3.0	MIT	MIT	MIT

† Flashbang and unduckified include no analytics scripts or tracking. Cloudflare Pages exposes basic request counts in its dashboard for all hosted sites — this is a platform-level metric we did not opt into and cannot disable. It is not Cloudflare Web Analytics.

Flashbang uses a different approach to the redirect step: a Service Worker intercepts the navigation request before the browser begins rendering, looks up the bang in a minimal in-memory map, and responds with a redirect. The bang data (867 KB, trigger→URL pairs only) is parsed once when the Service Worker installs and stays in memory across navigations. Other tools in this space parse their bang data on the main thread on each page load — the tradeoff they accept for a simpler architecture. Flashbang's settings UI is a separate bundle that only loads when you visit the page directly.

Note: Comparison data is accurate at time of writing. These projects are actively developed and may have changed since.

Acknowledgments

Flashbang was inspired by unduck by Theo Browne, which demonstrated the value of fast client-side bang redirects. Bang data is sourced from DuckDuckGo and Kagi.

Daily updates

A GitHub Actions workflow runs every 24 hours at 00:00 UTC to fetch the latest bang definitions from DuckDuckGo and Kagi, rebuild the generated JavaScript, and commit any changes. This keeps the bang database current without manual intervention.

Contributing

See DEVELOPMENT.md for prerequisites, build commands, and project structure.

License

AGPL-3.0 — see NOTICE.

Flashbang is designed to be self-hosted and most of projects in this space bundle analytics. AGPL ensures that anyone who deploys a modified version must share their changes — protecting end users from forks that quietly add tracking or degrade privacy. The project introduces a genuinely novel approach (Service Worker intercept, two-tier bang data, bang-aware suggestions), and AGPL ensures derivatives contribute back rather than just extract.