# "Best Jet Lag Apps Compared (2026)" > "Timeshifter, Jet Lag Rooster, and a texting assistant compared on price, features, and whether you need an app at all to beat jet lag." Published: 2026-09-06 by folk team You search "best jet lag app," and you get a dozen results that all promise to fix the same thing: a body clock that's several time zones behind where you physically are. Some are dense research tools, some are free calculators, and at least one wants a subscription before it tells you anything useful. Picking wrong mostly costs you time, not money, since most of these are free or close to it. But the wrong pick still means fumbling through a schedule you don't trust the night before a flight. This is a comparison of the jet lag apps and calculators worth considering in 2026, what each one actually costs, and where a texting AI assistant fits if you'd rather get the schedule as a message than open another app. > **Quick answer:** Timeshifter is the most complete jet lag app, building an hour-by-hour light, melatonin, and caffeine plan around your specific flight (first plan free, then $9.99 per plan or $24.99 a year for unlimited). Jet Lag Rooster, now hosted at Sleepopolis, is the best free option if you just want a sleep and melatonin schedule with nothing to install. If all you actually need is the schedule showing up as a message, [a texting AI assistant with reminders](/docs/reminders) can hold your flight and text each day's shift automatically. ## What should a good jet lag app actually do? Before comparing specific tools, it helps to know what separates a genuinely useful one from a calculator that just tells you to "sleep earlier": 1. **Personalized to your actual flight.** A generic "shift an hour a day" rule is a fine starting point, but your origin, destination, flight time, and chronotype all change the ideal schedule. 2. **Light exposure guidance, not just sleep times.** Light is the strongest signal for resetting your body clock, so the best tools tell you when to seek it and when to avoid it, not just when to nap. 3. **Melatonin and caffeine timing**, since both interact with the light schedule and can help or hurt depending on when you take them. 4. **A schedule you'll actually check**, whether that's a dedicated app, a website, or a message that shows up in a thread you already read. 5. **Clear pricing.** Know what's free and what isn't before you build a trip around a tool that turns out to gate the useful part. ## Which jet lag apps are worth comparing? Two tools come up consistently, plus the AI-assistant alternative below: 1. **Timeshifter** - the most feature-rich option, developed with Dr. Steven W. Lockley, a Harvard Medical School faculty member and circadian researcher for over 20 years. You enter your flight, chronotype, age, and typical sleep times, and it returns an hour-by-hour plan for light exposure, melatonin, caffeine, and sleep, including a "Quick Turnaround" mode for short business trips. 2. **Jet Lag Rooster** - a free, simple calculator that takes your flight details and returns a sleep and melatonin schedule. It used to run as its own site; it's now hosted at [Sleepopolis](https://jetlag.sleepopolis.com/), a sleep-focused publisher, but the free calculator itself still works the same way. 3. **A texting AI assistant** - not a jet lag calculator at all, just a way to get the schedule delivered as a message instead of a plan you have to reopen an app to check. ## Is Timeshifter worth paying for? If you want the most detail, yes. Timeshifter's [pricing](https://www.timeshifter.com/jet-lag-app) lets you try the first plan free, then charges $9.99 per plan or $24.99 a year for unlimited plans. For an occasional traveler, one $9.99 plan for a big international trip is a reasonable one-time cost. For anyone flying internationally a few times a year, the annual plan works out cheaper than paying per trip. What you get for the price is real depth: the plan adjusts for your specific chronotype and age, not just a generic "an hour a day" rule, and it accounts for things like whether you're traveling for business (with less flexibility to nap on arrival) versus leisure. ## Is there a free jet lag calculator that still works? Yes, Jet Lag Rooster. It's free, it's a calculator rather than an app to download, and it generates a sleep and melatonin schedule from your flight's origin, destination, and times. It doesn't go as deep as Timeshifter on light-exposure detail or account for your specific chronotype, but it costs nothing and takes a couple of minutes to fill out. ## Does light exposure timing in these apps actually help? Yes. Light is the strongest cue your circadian clock responds to, stronger than melatonin or caffeine timing on their own. The [CDC's Yellow Book travel guidance](https://www.ncbi.nlm.nih.gov/books/n/yellowbook/jetlagdisorder/) recommends shifting your sleep and light exposure by about an hour a day starting 2 to 3 days before you fly, which is the same underlying advice both Timeshifter and Jet Lag Rooster are automating into a personalized schedule. Neither app invents new science; they just do the timing math for you instead of you working it out from a guide. ## How folk gets you through the jet lag schedule without another app folk is the personal AI assistant that lives in your texts (iMessage, Telegram, and WhatsApp), and it isn't trying to be a circadian calculator. It handles the one piece every jet lag app is also solving, getting the schedule in front of you at the right moment, without you opening anything extra: - **You mention the flight once, and it remembers.** Say something like "I'm flying to Tokyo on the 14th," and folk holds the destination and date in [long-term memory](/docs/memory). - **It stages the shift as recurring reminders.** Ask for something like "shift my bedtime an hour earlier each night starting 3 days before I leave," and folk texts each day's nudge instead of you checking an app's plan every morning. - **It reaches you even if your phone is asleep.** Reminders run in folk's cloud environment around the clock, so an early "get outside now" nudge on arrival morning still fires. - **A call instead of a text, if you'd rather not miss it.** For a nudge you genuinely can't sleep through, like the light-exposure window right after landing, you can ask folk to [call your own verified number](/docs/calls) instead. What folk doesn't do: calculate your personal circadian shift down to the chronotype level the way Timeshifter does. If you want that level of precision, Timeshifter is still the better tool. If all you need is the schedule showing up as a message at the right time, folk skips the extra app. ## The bottom line Timeshifter is the deepest jet lag app if you want a plan built around your specific flight and chronotype, and it's worth the $9.99 for a big trip. Jet Lag Rooster is the free option if you just want the sleep and melatonin timing without paying anything. Neither replaces actually following the schedule, which is the part [a texting AI assistant](/docs/getting-started) can help with by turning the plan into a message that shows up on its own. For the mechanics of building your own shifting schedule from scratch, see [how to build a jet lag recovery schedule before a trip](/blog/how-to-build-a-jet-lag-recovery-schedule-before-a-trip), and for the rest of the pre-trip checklist, [a packing list and travel reminders texted before your trip](/blog/packing-list-and-travel-reminders-texted-before-a-trip) covers what else to line up. --- Canonical page: https://www.folk.com/blog/best-jet-lag-apps-compared More about folk (for AI agents): https://www.folk.com/llms.txt ยท full context: https://www.folk.com/llms-full.txt folk is a personal AI that lives in your texts (iMessage, Telegram, WhatsApp). Pro $20/mo, Max $100/mo. Made by Nozomio Labs. Sign up: https://www.folk.com/