Comparison

Seconds Interval Timer vs Onyx Timer

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Seconds Interval Timer

This interval timer app helps you build and run custom workouts for HIIT, Tabata, and circuits. It provides voice cues, runs in the background, and syncs with Apple Watch. Save workouts to Apple Health and track calories burned.

Highlights
  • Build custom timers for any workout
  • Voice cues for intervals
  • Runs in background with screen off
  • Syncs with Apple Watch
  • Color-coded interval display
  • Save workouts to Apple Health
  • Play music with cues
Features
Read full description

Seconds is an interval timer for HIIT, Tabata, EMOM, circuits and any workout built from timed intervals. It calls each interval out loud, keeps running with the screen off, and runs on iPhone, iPad and Apple Watch. Apple has featured it, and Joe Wicks, The Body Coach, has said it is the fitness app he uses more than any other. BUILD ANY WORKOUT - Start from a HIIT, Tabata or circuit template, or build a timer from scratch with sets, rounds and intervals of different lengths. - Chain timers into one compound timer, so a warm-up flows into the main set and then a cool-down. - Color-code every interval so you know what is coming before the beep. - Share a timer with a friend in one tap. HEAR IT, DON'T WATCH IT - Voice cues call out each interval by name and warn you before the next one starts. - Beeps and bells are there too if you would rather not be talked at. - Play your own music, per timer or per interval. Cues duck the music and it comes back up when they are done. - The timer keeps going in the background while you use other apps or the screen sleeps. ON THE GYM FLOOR - A full-screen, color-coded display you can read from across the room, in portrait or landscape. On iPad it uses the whole screen. - A lock button stops a stray tap from pausing your set. APPLE WATCH - Seconds runs on the watch by itself, so the phone can stay in the locker. Timers you build on the phone sync to the wrist, and Quick Intervals builds a basic circuit on the watch itself. MORE TIMERS - A stopwatch that marks your best and worst laps. - A countdown timer with five preset durations (three on Apple Watch). APPLE HEALTH - Save workouts and mindful sessions to Health. With a heart rate monitor connected, Seconds reads your body measurements and year of birth from Health to estimate calories burned. FREE TO TRY, ONE PAYMENT TO UNLOCK - Everything is available from the first launch. Build any timer and run it. - Each timer locks after you run it once. A single in-app purchase removes the lock on every timer you make. SECONDS AND SECONDS PRO - Seconds Pro is the same app, paid once up front, with nothing to unlock. The two are separate products and a purchase in one does not carry over to the other. If you bought Seconds Pro, download Seconds Pro. If you bought the unlock in Seconds, download Seconds and use Restore Purchases.

About

Onyx Timer

This app allows users to create and manage custom workouts combining time-based and rep-based exercises. Control your workout hands-free with voice commands and receive audio cues for each exercise. Workouts can be saved and shared, with options for visual and auditory customization.

Highlights
  • Voice-controlled timer
  • Mix time and rep-based exercises
  • Audio exercise announcements
  • Background operation
  • Workout saving and sharing
  • Customizable commands
Features
Read full description

Onyx is a talking timer app that lets you mix time-based and rep-based exercises in the same workout. Turn on listening mode to control the timer with your voice - after you're done with those pushups, simply say "next!" to go to the next exercise. Features: • Announces exercises in Siri's voice. • Customizable voice control commands for hands-free operation. • Runs in background, or with screen locked. • Listen to music while using the timer. • Optional beep and vibrate between exercises. • Workouts are saved to iCloud, or locally if iCloud is disabled. • Swipe screen to go forward or back. • Displays exercises as a running marquee. • Highly customizable. • Mix time-based and rep-based exercises in the same workout. • Add images and notes to exercises and color-code them. • In-depth help / operating manual. • Import and export workouts via email. • Dark and light skin.

Screenshots

Seconds Interval Timer4 screens
Onyx Timer4 screens

Verdict

The call

The clearest difference is rating: Seconds Interval Timer at 4.7 against Onyx Timer's 4.1. Seconds Interval Timer also leads on ratings volume (24K vs 17) and review sentiment (74% vs 65%). Onyx Timer's advantage is iOS requirement (7.0 vs 18.0). On price, update cadence, ads and in-app purchases there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Seconds Interval Timer sells 1 one-off in-app purchase and Onyx Timer sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

Seconds Interval Timer holds the better App Store score, 4.7 against 4.1. That said, the two scores are not equally well evidenced: Seconds Interval Timer has 24K ratings behind it against 17, so its average is the more settled of the two. Written reviews point the same way: 74% of Seconds Interval Timer's written reviews are positive against 65% of Onyx Timer's.

UpkeepUpdate frequency

Seconds Interval Timer ships an update monthly, Onyx Timer every 2 weeks. The most recent releases landed on November 10, 2026 and November 1, 2026 respectively.

Scorecard4 real differences · 6 level
Seconds Interval Timer versus Onyx Timer: the parameters behind the verdict, then further details
ParameterSeconds Interval TimerOnyx Timer
PriceFreeFree
Rating4.7 (24K ratings) — better4.1 (17 ratings)
Positive reviews74.5% of reviews — better65.2% of reviews
Number of ratings24K — better17
Update frequencyMonthlyEvery 2 weeks — better
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
DevicesiPhone, iPad, Apple Watch — betteriPhone, iPod
Requires iOS18.07.0 — better
Further details — not scored
Size99 MB35 MB
Age rating4+4+
DeveloperRunloop LtdKirill Edelman

Customer experience

Seconds Interval Timer

All ratings23,780 ratings
Positive92.9%
Neutral1.9%
Negative5.2%
Written reviews1,289 reviews
Positive74.5%
Neutral6.4%
Negative19.1%

Onyx Timer

All ratings16 ratings
Positive75.0%
Neutral0.0%
Negative25.0%
Written reviews23 reviews
Positive65.2%
Neutral0.0%
Negative34.8%

Bugs and requests

Seconds Interval Timer

Reported bugs

2 issues
  • Timer sometimes stops working unexpectedly
  • Issues with restoring purchases on new devices

Requested features

5 requests
  • Ability to change beep/alert volume independently
  • Option to delay transition between intervals
  • Sync workouts across devices
  • More preset workout templates
  • Heart rate monitoring integration

Onyx Timer

Not enough reviews yet to summarise bugs or requests.

In-app purchases

1 purchases

Seconds Interval Timer

One-time1
  • Advanced Version$7.99
1 purchases

Onyx Timer

One-time1
  • Remove Ads$0.99

Questions

Is Seconds Interval Timer free?
Seconds Interval Timer is free to download, with in-app purchases available.
Is Onyx Timer free?
Onyx Timer is free to download, with in-app purchases available.
Which has better reviews, Seconds Interval Timer or Onyx Timer?
Seconds Interval Timer is rated higher. Seconds Interval Timer averages 4.7 out of 5 from 24K ratings, while Onyx Timer averages 4.1 from 17 ratings.
Do Seconds Interval Timer or Onyx Timer have ads?
Neither Seconds Interval Timer nor Onyx Timer shows ads.
Which is updated more often, Seconds Interval Timer or Onyx Timer?
Seconds Interval Timer ships an update monthly, and Onyx Timer every 2 weeks. Most recently, Seconds Interval Timer was updated on November 10, 2026 and Onyx Timer on November 1, 2026.

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