Web app · Health And Fitness
Tortoise
Couch to 5K that lets you actually finish
The same proven walk-run structure, but the plan advances only when your last run stayed under your aerobic ceiling — otherwise you repeat the week. Three pace plans (12, 9 or 6 weeks), a full-screen interval runner with three voice coaches, and treadmill mode with no pace shaming. Free, no install.
Stored in your browser only. Nothing you do in the web version is sent to our servers. Clear your browser data and it's gone — so export a backup from the in-app menu if you want to keep it.
This app is a community proposal.
Try the full browser version now. We build the iPhone and Android app once 100 people upvote it.
We'll email you once, when it ships. Unsubscribe anytime.
In your browser
What you can do in Tortoise on the web
Three pace plans, picked up front
Tortoise over 12 weeks with the smallest possible jumps, Standard over the classic 9, or Hare over 6 for returners — every week's real interval table, three workouts a week.
The heart-rate gate
After each run you say whether you held your ceiling. Held it and next week opens; struggled and the calendar rewinds seven days so you repeat the week. No shame, just biology.
Full-screen interval runner
A colour-changing countdown ring per interval, run and walk cues, up-next, elapsed and remaining, skip and back — and a “Done.” screen that logs the run.
Three voice coaches
Drill sergeant, patient friend, or silent beeps — spoken through your browser with the same lines as the iPhone app, and you can preview every cue before you set off.
Treadmill mode
Switch to time-only intervals with no pace targets, because the dominant Couch-to-5K apps have years of complaints about wildly wrong treadmill paces.
A quiet run log
Every finished workout with its week, minutes, average heart rate and whether it held target — plus workouts-per-week bars and an HR trend against your ceiling. No leaderboard, no social.
Screens
Every screen, rebuilt for the browser
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1
Today
Which week you are on, today's workout with every interval, the gate, treadmill and coach status, and plan progress.
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2
Plan
The pace picker and the full week list for your plan, with each week's summary, minutes and running time.
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3
Week detail
One week's workout in full — every interval, the running total, and the option to jump the plan there.
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4
Workout runner
The full-screen interval timer with the countdown ring, voice cues, controls and the finish screen.
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5
Heart-rate gate
Your aerobic ceiling, whether the last run held it, how the gate works, and your held-back-week count.
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6
Treadmill mode
Time-only intervals versus an outdoor pace target, and why the toggle exists.
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7
Voice coach
Drill sergeant, patient friend or silent beeps, with a preview of every interval cue.
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8
Run log
Workouts, minutes and held-target rate, workouts per plan week, average heart rate against your ceiling, and every run.
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9
Settings
Plan, start date, weeks held back, coach, treadmill, gate, CSV and JSON export, restart and erase.
Try it with sample data: Puts you four weeks into the Tortoise plan with fourteen logged runs, including the hard week-2 session at 158 bpm that held the plan back and the three repeat workouts that followed. You can start fresh at any time.
Ready? It's free.
No account, no install, no subscription. Everything you do stays in this browser.
Your say
What should Tortoise do? Tell us before we build it.
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Questions
Is the web version of Tortoise free?+
Yes. Every screen is free to use: no subscription, no in-app purchases, no account.
Do I need an account?+
No. Open Tortoise and start using it right away. Sign in with Google only if you want to upvote an app, save it to your list, or leave a comment.
Where is my data stored?+
Only in this browser's local storage. Nothing you enter is sent to our servers, so we can't see it, back it up, or restore it. Clearing site data, a private window, or another device starts empty. Export a backup from the in-app menu to keep it.
Is there a Tortoise app for iPhone or Android?+
Not yet. Tortoise is a community proposal: the browser version is complete, and we build the iPhone and Android app once 100 people upvote it. Upvoters get one email when it ships.