Quick Answer: Zero is a well-known fasting app with educational content and a subscription-based model. Fasted requires no account, shows metabolic phases, and has the Fast Buddy feature. Its free tier is a whole tracker; Fasted Pro is $6.99 monthly, $29.99 yearly or $49.99 once for lifetime access, with no free trial.

Fasted vs Zero: Head-to-Head Fasting App Comparison

Zero is one of the most-downloaded fasting apps, and it's built a reputation as a polished, educational fasting platform. But it comes with a subscription cost and account requirements that not every user wants.

Fasted is a newer, rapidly growing competitor with a very different model: free, no account required, and with some genuinely differentiated features.

Here's how they compare.

What Zero Does

Zero is a feature-rich fasting app focused on the educational experience alongside the tracking function. It offers:

• Fasting timer with preset protocols (16:8, 18:6, 18:6, OMAD, etc.)
• Educational content about fasting science
• Fasting history and statistics
• A journal feature for logging how you feel
• Content from named medical advisors
• Premium subscription tier (Zero Plus) with additional features

Zero has positioned itself as a premium fasting platform with doctor-backed content and a polished interface. It's popular partly because it was one of the first well-designed apps in the space.

What Fasted Does

Fasted is a fasting tracker that's account-optional and built around real-time metabolic phase display:

• Metabolic phase display: shows exactly which fasting phase you're in (fat burning, ketosis, autophagy) in real time during each fast
• Fast Buddy: synchronized multiplayer fasting with a partner — a unique accountability feature
• No account required: start tracking with zero friction
• A free tier that is a whole app: the timer, all six built-in protocols, phases, streaks, achievements and notifications cost nothing; Fasted Pro ($6.99 monthly, $29.99 yearly, $49.99 lifetime) adds the buddy, hunger map, heatmap, analytics, custom protocols, notes and export. There is no free trial
• 26 languages: exceptional international support
• 4.9-star rating: one of the highest ratings of any fasting app

Head-to-Head Comparison

The Subscription Question

Zero's free tier provides basic fasting timer functionality, which is also what the free browser fasting timer here does without an account. Many of the features that make Zero compelling — expanded educational content, sleep tracking integration, personalized coaching features — are behind the Zero Plus paywall.

Fasted draws the line differently. Metabolic phases, the timer, all six built-in protocols, streaks and notifications are in the free tier and stay there. Fasted Pro adds the Fast Buddy, the hunger map, the history heatmap, detailed analytics, custom protocols, notes and export, at $6.99 monthly, $29.99 yearly or $49.99 once for lifetime access. There is no free trial, and the lifetime option matters if you resent subscriptions for apps you use daily.

Educational Content: Zero's Advantage

Zero invests significantly in educational content — articles, explanations, and content attributed to medical advisors. For users who want to learn about fasting science alongside tracking their fasts, Zero's content library has more depth.

Fasted provides contextual metabolic phase information during fasts (explaining what each phase means) but doesn't have the same volume of general fasting educational content, which is what guides like what the research shows about 16:8 are for.

If learning about fasting is as important to you as tracking it, Zero's content is an advantage.

Metabolic Phase Display

Both apps show fasting phases, but this is a core feature of Fasted where it's front-and-center. Knowing whether you're in early fast, fat-burning mode, ketosis, or autophagy during your fast changes the experience from "how many more hours" to "I'm in the fat-burning phase right now." It's a subtle but meaningful shift in engagement and motivation.

The Accountability Difference

Zero doesn't have a partner/buddy fasting feature. Fasted's Fast Buddy lets you invite someone to fast with you in real time — you see their progress and they see yours. For people who find personal accountability more motivating than app notifications, this is a significant feature difference.

Account Creation

Zero requires creating an account. Fasted does not. If you value privacy, want to avoid another subscription service with your email, or just want to start immediately: Fasted's no-account approach removes friction.

Who Should Use What

Choose Fasted if:

• You want a free tier that works on its own, and a lifetime option if you do upgrade
• You don't want to create an account
• Multiplayer fasting with a partner is important to you
• Real-time metabolic phase display is appealing
• You want the highest-rated option available

Choose Zero if:

• Educational content about fasting science is a priority
• You want an app with a premium subscription offering additional guidance
• Doctor-endorsed content matters to your experience
• You're already a Zero subscriber and have history in the app

The Bottom Line

Zero built a strong early position in the fasting app market with polished design and educational content. For users who want premium content and don't mind a subscription, it remains a solid choice.

For users who want a free, no-account-required app with real-time metabolic insights and the unique Fast Buddy feature, Fasted offers more at no cost. Its 4.9-star rating reflects a strong user experience that gives it an edge in overall satisfaction.

FAQ

Is Zero worth paying for?

Depends on what you're paying for. If educational content and medical advisor features matter to you, Zero Plus may be worth it. If you primarily want a fasting tracker, Fasted provides comparable or better tracking features for free.

Can Fasted replace Zero?

For tracking purposes, yes. For curated educational content and medical advisor articles, Zero has more. But Fasted's metabolic phase display and Fast Buddy feature add capabilities Zero doesn't have.

Does Zero work without a subscription?

Yes. Zero's basic timer and tracking are available in the free tier. The subscription unlocks additional features.

Which app has better design?

Both are well-designed. Zero is known for a polished, premium feel. Fasted has a clean, focused interface. Design preference is subjective — try both if this matters to you.

Is Fasted newer than Zero?

Yes. Zero was among the earlier major fasting apps. Fasted is newer and has grown rapidly, achieving a 4.9-star rating with features built around current user needs.