Intervals.icu Pricing 2026: Is It Really Free? (Supporter Tier Explained)

TL;DR: Yes, Intervals.icu is really free, and the free tier is not a stripped-down teaser. Fitness, fatigue and form tracking, the power curve, automatic interval detection, the training calendar, the workout builder and device sync all cost nothing, with no time limit and no credit card. The optional Supporter tier costs 4 dollars per month and adds extras: an annual training plan builder, full Strava history import, fully custom zones, weather analysis, and teams and coaching organisations. For self-coached athletes, free covers everything that matters. For coaches, the real cost of Intervals.icu is not the subscription, it is everything the platform doesn’t do: no billing, no client reports, no testing, no dedicated support. Those gaps get filled with other tools, time, or both.

Intervals.icu Pricing Overview

Intervals.icu takes the simplest pricing approach in endurance software: the platform is free, and people who want to support its development pay a voluntary 4 dollars per month for the Supporter tier. There are no athlete counts, no per-seat fees, no feature-gated coach editions, and no trials because there is nothing to trial your way into.

This model works because Intervals.icu is not a company in the usual sense. It is built and run by David Tinker, a developer and cyclist in Cape Town who started the platform in 2018 as a side project analyzing his own Strava data and went full-time on it in 2024. Supporter subscriptions fund the work. More than 160,000 active athletes use the platform, and 193 million+ activities have been analyzed.

The Free Tier

The free account includes the complete analysis and planning core:

• Fitness, fatigue and form tracking: The full Performance Management Chart model (CTL/ATL/TSB), the chart TrainingPeaks reserves for its paid Premium tier
• Activity analysis: Automatic interval detection, power and pace charts, decoupling analysis, zone time distribution
• Power curve and HR analytics: Multi-season comparison, watts per kilogram, eFTP estimation and multiple power models
• Training calendar and workout builder: Drag-and-drop planning, structured workouts with power, heart rate, pace or cadence targets, ZWO/FIT/MRC/ERG import and export
• Device and platform integrations: Garmin, Polar, Suunto, COROS, Wahoo, Strava, Zwift, MyWhoosh, Rouvy, Oura, Whoop, Concept2 and more
• Multisport support: Separate zones and settings per sport
• Custom charts: Build your own visualizations

No credit card is required, and there is no expiry. This is the full product for the overwhelming majority of users.

The Supporter Tier: 4 Dollars per Month

The Supporter subscription unlocks a set of additional features:

• Advanced weather analysis
• Annual training plan builder
• Import of full Strava history
• Route matching and automatic commute flagging
• Customizable activity summary
• Completely custom zones (zones for any activity stream, anchored to any field)
• CSV upload of activity stream data
• Teams and coaching organisations
• Bulk athlete configuration
• Early access to beta features
• Priority for feature requests

Two of these matter specifically for coaches: teams and coaching organisations, and bulk athlete configuration. A coach running a group of athletes on Intervals.icu will in practice want the Supporter tier. At 4 dollars per month, that is still the cheapest coach-capable subscription in endurance software by a wide margin.

What “Free” Buys You, Honestly

It is worth pausing on how unusual this is. The analytical core of Intervals.icu overlaps heavily with TrainingPeaks Premium, which costs around 20 dollars per month for athletes, and with coach platforms costing 20 to 55 dollars per month. Reviewers regularly describe cancelling paid subscriptions after moving their analysis to Intervals.icu, and the platform’s own testimonials include exactly that story.

There is no catch in the usual sense. No ads, no selling of data, no artificial limits designed to push you to a paid tier. The Supporter price is set low deliberately, and the developer has kept the important features free as a matter of stated principle.

The honest caveat is structural rather than hidden: you are relying on a platform funded by goodwill and run by one person. That has worked well since 2018 and the project is clearly healthy. But there is no company, no SLA and no dedicated support organization behind it, which matters more the more professional your use of it becomes.

The Real Costs for Coaches

For a professional coach, the subscription price is the smallest part of the calculation. The real costs of building a coaching practice on Intervals.icu come from what it does not include.

No Billing or Client Administration

Intervals.icu has no athlete billing, no subscription automation and no invoicing. Coaches charge clients through separate tools (Stripe, bank transfers, accounting software) and spend administration time gluing it together. Platforms built for coaching businesses automate this. Intervals.icu does not try to, and its developer has been clear that it is an analysis platform first.

No Physiological Testing

There is no lactate testing module, no threshold detection from test data, and no zone generation from physiological assessments. The eFTP estimation from field data is genuinely useful, but coaches who run lactate step tests need separate software for the analysis, and every retest ends with manual zone entry. If testing is part of your service, that is a recurring time cost and a second subscription.

No Client-Ready Output

Intervals.icu produces charts for you, not reports for your clients. There are no branded PDF reports to hand to a paying athlete after a test or a season review. Coaches who charge for testing or reviews build those deliverables by hand.

Support Is the Community

Questions go to the Intervals.icu forum, where answers are usually fast and friendly. But there is no support team with response times, which is a different proposition when a sync failure hits during a paying client’s race week.

The Learning Curve, Multiplied by Your Roster

The platform is dense and web-first, and its mobile experience trails the desktop. A data-savvy athlete pushes through the learning curve happily. A roster of 20 athletes with mixed technical appetite will not all make it, and the coach absorbs the support burden. This is a real, if unquantifiable, cost of putting client-facing workflows on a power tool.

Is Intervals.icu Good Value?

For self-coached athletes: the best value in endurance sport, and it is not close. The free tier covers everything most athletes need, and the 4 dollar Supporter tier covers the rest for less than the price of a coffee. If that describes you, sign up and consider supporting the project.

For coaches, the answer depends on what your practice needs. If your coaching is analysis guidance for self-sufficient athletes, Intervals.icu plus the Supporter tier is a complete and nearly free toolkit. If your practice includes client billing, professional reports, physiological testing, or athletes who need a guided experience, Intervals.icu covers one part of your stack and leaves the rest to other tools. The full picture is in our Intervals.icu Review.

How Coachbox Pricing Compares

Coachbox sits at the other end of the same spectrum: a paid platform built specifically for the coaching practice, with testing included and the business features either built in or on the roadmap.

Coachbox Coach Plans

Every coaching plan comes with a set of free lactate tests when you join, with the number depending on the plan you choose. After that, tests are priced per test. All plans include the complete platform: training planning, athlete communication, calendars, analytics, annual periodization, device sync for Garmin, Wahoo, Polar, Suunto, COROS, Fitbit and TomTom, zone management that auto-updates from test results, and Coachbox AI, an assistant you can chat with about your athletes’ data. There is a 14-day free trial, no credit card required, and athletes always use the app for free.

What You Get That Intervals.icu Doesn’t Offer

Where Intervals.icu Has the Advantage

The comparison is honest in both directions. On price and analytical freedom, Intervals.icu wins outright. On the professional coaching workflow, testing, reports, communication, education and support, Coachbox covers ground Intervals.icu does not attempt.

Side-by-Side Pricing Comparison

When Intervals.icu’s Pricing Makes Sense

You coach yourself. There is no better deal anywhere. Take the free tier, and if the platform earns a place in your daily training, the Supporter subscription is a fair way to keep it alive.

You coach a few self-sufficient athletes. The Supporter tier’s teams and bulk configuration features turn Intervals.icu into a functioning coach toolkit for 4 dollars per month, provided your athletes are comfortable in a data-dense interface and you handle billing and reporting elsewhere.

You want analysis alongside another platform. Many coaches and athletes run Intervals.icu next to their primary platform purely for its charts. At zero cost, it earns that spot easily.

When Coachbox’s Pricing Makes More Sense

You test your athletes. Lactate testing is built into every Coachbox plan, with free tests at signup and automatic LT1/LT2 detection and zone updates. Next to Intervals.icu you would need separate testing software and manual zone transfers, and the time cost alone usually exceeds the subscription difference.

Your athletes are clients, not power users. Coachbox is built so athletes get a guided app in their own language (seven available), with structured communication back to you. You are not asking paying clients to learn a data workbench.

You charge for professional deliverables. Branded test reports and a professional client experience are part of what justifies your rates. A EUR 12.95 to 39.95 monthly plan that produces them is a business expense that pays for itself.

You want a company behind your workflow. Dedicated support and a product roadmap built around coaching practices matter when the platform is how you earn your living. See the full comparison in Coachbox vs Intervals.icu.

Making Your Decision

Choose Intervals.icu if you are self-coached or coach a small group of data-comfortable athletes, and your practice does not depend on testing, billing or client reports. It is free, brilliant at analysis, and supported by a community that deserves its reputation.

Choose Coachbox if coaching is your profession and you want testing, communication, client-ready output and support in one subscription. From EUR 12.95 per month with a 14-day trial and no credit card, the cheapest way to decide is to run it alongside Intervals.icu for two weeks and see which one carries more of your actual work.

And if you are comparing the free option against the industry standard instead, read Intervals.icu vs TrainingPeaks or our TrainingPeaks Pricing breakdown.