History-based estimates

Apple OS Release Forecasts

Public-release and next-milestone windows derived from comparable Apple beta cycles. Every estimate includes its cohort, sample size, historical spread, and a safeguard against stale source data.

Calculated as of Jul 29, 2026. Data refreshes automatically after Sanity updates.

Tracked Cycles

Active Forecasts

Paused / Stale

Backtest Median Error

Historical backtest

In 32 rolling tests, each release was estimated using only cycles already public at that point—never later data. The median absolute error was 5 days, and the actual date fell inside the historical 25th–75th percentile window in 53% of tests. Historical performance is not a promise of future accuracy.

Current release cycles

Forecasts pause automatically when the latest recorded milestone is more than 60 days old or the entire historical window has elapsed.

iOS27.0

Latest recorded milestone: Beta 4 on Jul 20, 2026

Higher historical confidence

Forecast active

Current estimate based on the latest recorded milestone and comparable historical cycles.

Estimated public release window

Sep 7, 2026–Sep 15, 2026

Historical median: Sep 12, 2026

Estimated next milestone window

Aug 1, 2026–Aug 3, 2026

Most often Beta 5 (100% of comparable cycles; n=12)

Comparable cohort

iOS .0 cycles at Beta 4

12 cycles: 26.0, 18.0, 17.0, 16.0, 15.0, 14.0, 13.0, 12.0, 11.0, 10.0, 9.0, 8.0

Range definition

25th–75th percentile of observed days from Beta 4 to public release.

Prior-only backtest for this platform and release class: 6-day median error; 50% inside the historical range across 10 tests.

iPadOS27.0

Latest recorded milestone: Beta 4 on Jul 20, 2026

Higher historical confidence

Forecast active

Current estimate based on the latest recorded milestone and comparable historical cycles.

Estimated public release window

Sep 9, 2026–Sep 13, 2026

Historical median: Sep 11, 2026

Estimated next milestone window

Jul 31, 2026–Aug 2, 2026

Most often Beta 5 (100% of comparable cycles; n=7)

Comparable cohort

iPadOS .0 cycles at Beta 4

7 cycles: 26.0, 18.0, 17.0, 16.0, 15.0, 14.0, 13.0

Range definition

25th–75th percentile of observed days from Beta 4 to public release.

Prior-only backtest for this platform and release class: 2-day median error; 75% inside the historical range across 4 tests.

macOS27.0

Latest recorded milestone: Beta 4 on Jul 20, 2026

Low historical confidence

Forecast active

Current estimate based on the latest recorded milestone and comparable historical cycles.

Estimated public release window

Sep 15, 2026–Oct 18, 2026

Historical median: Oct 4, 2026

Estimated next milestone window

Aug 2, 2026–Aug 3, 2026

Most often Beta 5 (100% of comparable cycles; n=6)

Comparable cohort

macOS .0 cycles at Beta 4

6 cycles: 26.0, 15.0, 14.0, 13.0, 12.0, 11.0

Range definition

25th–75th percentile of observed days from Beta 4 to public release.

Prior-only backtest for this platform and release class: 34-day median error; 0% inside the historical range across 3 tests.

watchOS27.0

Latest recorded milestone: Beta 4 on Jul 20, 2026

Higher historical confidence

Forecast active

Current estimate based on the latest recorded milestone and comparable historical cycles.

Estimated public release window

Sep 9, 2026–Sep 18, 2026

Historical median: Sep 13, 2026

Estimated next milestone window

Aug 2, 2026–Aug 3, 2026

Most often Beta 5 (100% of comparable cycles; n=11)

Comparable cohort

watchOS .0 cycles at Beta 4

11 cycles: 26.0, 11.0, 10.0, 9.0, 8.0, 7.0, 6.0, 5.0, 4.0, 3.0, 2.0

Range definition

25th–75th percentile of observed days from Beta 4 to public release.

Prior-only backtest for this platform and release class: 5-day median error; 50% inside the historical range across 8 tests.

tvOS27.0

Latest recorded milestone: Beta 4 on Jul 20, 2026

Higher historical confidence

Forecast active

Current estimate based on the latest recorded milestone and comparable historical cycles.

Estimated public release window

Sep 7, 2026–Sep 15, 2026

Historical median: Sep 13, 2026

Estimated next milestone window

Aug 1, 2026–Aug 3, 2026

Most often Beta 5 (100% of comparable cycles; n=10)

Comparable cohort

tvOS .0 cycles at Beta 4

10 cycles: 26.0, 18.0, 17.0, 16.0, 15.0, 14.0, 13.0, 12.0, 11.0, 10.0

Range definition

25th–75th percentile of observed days from Beta 4 to public release.

Prior-only backtest for this platform and release class: 2-day median error; 71% inside the historical range across 7 tests.

visionOS27.0

Latest recorded milestone: Beta 4 on Jul 20, 2026

Low historical confidence

Forecast active

Current estimate based on the latest recorded milestone and comparable historical cycles.

Estimated public release window

Sep 13, 2026–Oct 17, 2026

Historical median: Sep 13, 2026

Estimated next milestone window

Aug 3, 2026–Aug 11, 2026

Most often Beta 5 (100% of comparable cycles; n=3)

Comparable cohort

visionOS .0 cycles at Beta 4

3 cycles: 26.0, 2.0, 1.0

Range definition

25th–75th percentile of observed days from Beta 4 to public release.