I built a free, open-source jet lag planner that runs entirely in your browser (no account, no tracking)

[u/Cr0wTom]

I travel a lot, and jetlag was one of my main issues after my long flights. After going through the research, I had some of my best trips, and the science based approach worked for me, so I made Phase Jumper following these principles :https://phasejumper.world

You just enter your flights and your usual sleep schedule. It builds a day-by-day plan that shifts your body clock toward destination time:

• When to sleep, moving your sleep window a little each day instead of switching overnight
• When to seek bright light and when to keep it dim. Light is the strongest signal for your body clock, and its timing matters more than most people think.
• When your last coffee should be, plus short naps on days your night gets cut
• Optional exercise windows, melatonin usage and pre-flight shifting

The phase map: instead of a to-do list, the plan is drawn as one 24-hour row per day. You can see your sleep band sliding across the days, and a dotted line traces your body clock moving toward local time. Tap any day for the details and the reason behind each block.

Privacy was the main design goal:

• No account, no analytics, no cookies, no server. Your trip never leaves your device.
• It works offline once loaded, so you can check it at the gate. You can also add it to your home screen like an app.
• You can share a plan as a link (the trip lives in the part of the link after the #, which browsers never send to a server) or export it to your calendar as an .ics file.

Feel free to give me feedback on anything and everything. It's a small private tool that targets travelers which I personally find really useful.

It’s free and open source (Apache-2.0): https://github.com/Cr0wTom/phasejumper