ZLayer is a free, open-source electronic flight bag (EFB) and flight planner for phones, tablets and desktops. Use it to plan routes on FAA charts, read approach plates, and check aviation weather and NOTAMs. It runs in a browser and can be installed as a progressive web app (PWA), with regional downloads for offline use.
You can use it at zlayer.tedyin.com. You don't need an account or subscription, and ZLayer will stay free. The About page has answers to common questions about installation, offline use and data sources.
Check chart editions and weather times in the app; the screenshot is an example.
- Charts and navigation: FAA VFR sectionals and IFR low/high charts, with search for airports, NAVAIDs, fixes and VFR waypoints.
- Routes: Plan with airports, fixes and airways, look up preferred and TEC routes, preview published procedures, and save named routes locally.
- Weather: METARs, TAFs, PIREPs, advisories, AWC/WPC analysis and forecasts, cloud, icing and wind fields, and NOAA radar with recent history.
- Plates and notices: Approach plates, airport diagrams, Chart Supplements, airport and procedure NOTAMs, and graphical TFRs.
- Map tools: Terrain along a route or across the map, FAA obstructions, glide planning, distance measurement and optional device GPS.
- Offline downloads: Download charts and data for supported U.S. states and territories. Settings shows progress, chart editions and storage status.
ZLayer remembers your route, map position, open panels and place in a plate when you reload. The Route Stash saves named routes, including feature pins and approach attachments, for later use.
- Open zlayer.tedyin.com in a browser with WebGL2.
- To install on iPhone or iPad, use Safari → Share → Add to Home Screen. On Android, use Chrome's install or Add to Home Screen option. You can also use a desktop browser tab.
- For offline use, open Settings → Offline, download your regions, and wait for Saved. On iOS, install first and download inside the installed app. Disconnect from the network and check the charts and plates you need before relying on them offline.
Routes, settings and downloads belong to the browser or installed app where you saved them. They do not sync between devices; you can copy or share route text to move a route to another device.
A regional download includes VFR and IFR low/high charts, navigation data, applicable procedure and Chart Supplement books, and plates available only as individual files. Verified saved editions stay in use through feed updates and outages. Choosing a different date to browse does not change your saved edition. Files you view also enter the cache, but that does not mean the whole region has been saved. See offline storage for details.
Regional downloads do not include complete satellite basemap coverage. Fresh weather needs an internet connection, and FAA charts and procedures are limited to the coverage available in the feed. Downloads along a route corridor and satellite weather imagery are still planned; the roadmap tracks those and other remaining work.
ZLayer targets modern desktop browsers, Android Chrome and iOS/iPadOS Safari 18+. Offline use, low-storage behavior, GPS and performance still need testing in installed iOS and Android apps before release. Desktop browser tests can't cover those checks. See browser compatibility and offline storage for the requirements.
ZLayer is a supplemental planning tool, not an official briefing source or a certified EFB. It does not file flight plans, calculate fuel or aircraft performance, or assure terrain clearance. The experimental AHRS toolbox has not been validated in flight.
Use Node.js 24 or newer and run commands from the repository root:
npm ci
npm run devThe development server proxies weather and NOTAM requests to https://zlayer.tedyin.com
and FAA chart assets to charts.tedyin.com. This uses the same data feeds as
production. To run your own weather and NOTAM backend, see the
info server guide.
The app lives in src/, the info server in tools/info-server/, tests in test/,
and local proxy rules in tools/dev-proxy.ts. Only packages/contracts and
packages/domain are npm workspaces. npm run build produces the static site in
dist/; the deployment guide covers hosting it
and putting the info server behind an HTTPS reverse proxy.
Run npm run verify:standard and focused tests for affected behavior before
committing, subject to the server-only scope rule in
AGENTS.md. Use npm run verify:full
for exhaustive verification before releases. The
verification guide lists
browser prerequisites, focused commands, and the local and GitHub CI checks.
Cached charts and routes load first, then refresh in the background. FAA features and weather render as MapLibre layers rather than individual DOM markers. Airport details open the selected procedure or minimums page directly. Layers show their data source and valid time, and flag stale, incomplete or unavailable data. The design principles explain these choices.
faa-regs generates the FAA chart, NASR and d-TPP feed. ZLayer reads chart coverage
from its manifests and provides the map, routing, weather, procedure viewer and
offline storage. The basemap stays visible outside the available chart coverage.
- Documentation index
- Direction and principles
- Current capabilities and roadmap
- Architecture
- Layer design and source layout
- Local development and verification
- Offline storage, regional downloads and device checks
- Deployment and hosting
Copyright (C) 2026 ZLayer contributors.
Except where otherwise noted, ZLayer's original source code and accompanying
documentation are licensed under the GNU Affero General Public License,
version 3 only (AGPL-3.0-only). You may redistribute and modify this software
under those terms; see LICENSE for the full license. It is provided
without any warranty, including the implied warranties of merchantability or
fitness for a particular purpose.
Commercial use and forks are welcome. Distributing a covered version requires providing its corresponding source under the AGPL. If you modify the program and let users interact with that version remotely over a network, you must prominently offer those users its corresponding source at no charge. The full license governs these obligations; contributing changes upstream is welcome but is not required.
Separately licensed material retains its existing terms and notices, including the SIL Open Font License for the bundled Noto glyphs, and third-party dependencies. Incorporated public-domain material remains public domain. Aviation data, charts, map tiles and other external content are subject to their own source terms; see the source register.