Look back at what happened earlier

Steps

1. 01Step 1 of 9

   Step 1. The last two minutes: point at the timeline

   On Overview (⌘1), the card Live timeline draws CPU, GPU, Neural Engine, memory, disk and network on one clock. Move the pointer over any lane. A line follows it through every lane, and the whole stage above rewinds to that moment.

   Click to pin the moment. Click the × on the chip beside the title to go back to live.

   OverviewUnderstand what your Mac is doing, and what is using its resources.

   SummaryDashboardSearch or jump to…⌘KPauseRecord

   Inspecting10:41:32

   This Mac had capacity to spare.

   Whole-Mac readings from this sample. Workloads below follow the displayed sample.

   Pressure NormalThermal Nominal

   486 processes · 3,912 threadsUp 4d 3h · swap 0 bytes

   Export Visual Snapshot…

   Apple M4 Prosystem on chip · 14 CPU cores · 48 GB unified memory

   CPUwhole Mac · every 2s

   24%

   User17.6%System6.4%Idle76.0%

   GPUevery 5s

   18%

   Renderer16%

   Tiler9%

   Neural Engine

   0.42W

   power, not utilizationpeak 2.31 W · 120 s

   Unified memoryshared by CPU, GPU and Neural Engine

   21.4GBestimated used of 48 GB · 44.6%

   App14.2 GBWired4.1 GBCompressed3.1 GB

   Cache12.8 GBFree13.8 GB

   Component power

   14.2Wpeak 31.6 W

   CPU 9.6 · GPU 4.2 · ANE 0.42 W

   Diskevery 2s

   Read2.1 MB/s

   Write1.1 MB/s

   Networkevery 2s

   Received1.6 MB/s

   Sent210 KB/s

   Live timelineLatest 120 seconds on one clock · hover to rewind the stage, click to pin · gaps stay visibleInspecting 10:41:32

   CPUevery 2s

   24%User 17.6% · System 6.4%

   100%0

   GPUevery 5s

   18%Renderer 16% · Tiler 9%

   100%0

   Neural Engineevery 5s

   0.42 Wpower, not utilization

   2.5 W0

   Memoryevery 2s

   21.4 GBPressure Normal

   48 GB0

   Diskevery 2s

   3.2 MB/sRead 2.1 · Write 1.1 MB/s

   ↑ 20 MB/s↓ 20 MB/s

   Networkevery 2s

   1.8 MB/sReceived 1.6 MB/s · Sent 210 KB/s

   ↑ 5 MB/s↓ 5 MB/s

   Apps using CPUApp helpers are included · 100% means one busy core

   L

   Lumen Edit6 processes

   212.4%

   K

   Kite Browser23 processes

   38.6%

   F

   Forge IDE14 processes

   24.9%

   H

   Harbor9 processes

   18.2%

   R

   Roundtable5 processes

   9.8%

   Sample 10:42:18Explore all processes

   What the numbers meanObservations from the displayed sample

   Info

   Lumen Edit leads measured CPU usageIt uses 212.4% CPU across 6 processes, where 100% is one core.

   Info

   Memory pressure is normalmacOS is meeting demand without heavy compression or swap.

2. 02Step 2 of 9

   Step 2. The last half hour: open History

   Press ⌘7. The view Recent details keeps every sample of the last 5, 10 or 30 minutes, with the apps and processes that were running in each one. The strip across the top is CPU for the whole Mac, with the highest moments flagged.

   History

   Recent detailsSummariesWeekly reportSaved app historySearch or jump to…⌘KPauseRecord

   Live · latest in view10:42:18

   24.0%

   Mac CPU100% = whole Mac

   Lumen Edit is the largest workload.

   In the latest sample it used 212.4% CPU across 6 processes, where 100% is one core.

   Pressure NormalThermal Nominal

   Recent detailsEvery sample keeps its apps and process lifetimesMac CPU

   12345

   100%50%0%

   10:12:2010:27:1910:42:18

   Previous sampleNext sampleSample 900 of 900 · 486 processes

   Click or drag to inspect the workloads at that time. Choose a workload below to see its resource history.

   Largest peaksHighest Mac CPU samples in this window, at least 1m 29s apart · select one to move the playhead

   196.8%10:31:06257.1%10:32:40330.5%10:38:06427.8%10:17:06526.2%10:35:46

   Recent activitySaved sessions

   10:12:20 – 10:42:18 · 900 samples · 29m 58s retained

   Recent history updates on screen about every 5 seconds. The actual retained window is limited by time, samples, and process count.

   Average Mac CPU25.0%1,798 measured seconds

   Observed workloads2129 no longer present

   Average used memory21.2GBTime-weighted observed memory

   Workloads across this historyFind an app or executable

   Sorted by measured CPU-seconds. Exited apps remain available for inspection. A partial label means some process measurements are unavailable.

   WorkloadCPU-secondsAverage CPUPeak memory

   LLumen Edit9 lifetimes3,014.1167.6%9.4 GB

   PPixelroom4 lifetimes · exited806.4170.1%2.8 GB

   KKite Browser26 lifetimes · partial740.841.2%4.6 GB

   Kkernel_task1 lifetime406.322.6%2.4 GB

   FForge IDE14 lifetimes361.420.1%3.2 GB

   WWindowServer1 lifetime321.817.9%1.3 GB

   HHarbor9 lifetimes312.917.4%5.6 GB

   RRoundtable5 lifetimes172.69.6%940 MB

   212 of 212 workloads · 9 exited

   L

   Lumen Edit/Applications/Lumen Edit.app

   Show history forAll processes in this workload

   ResourceCPUGPU timeMemoryDisk readDisk writeReceivedSent

   CPU100% = one core

   1,000%500%0%

   10:12:2010:27:1910:42:18

   The axis is one core. A workload can pass 100%.

   Workload read: 3.4 GB in 1,798.0 measured secondsWorkload written: 11.2 GB in 1,798.0 measured seconds

   Processes at 10:42:18

   ProcessCPUMemory

   Lumen Edit · PID 4812128.4%3.9 GB

   Lumen Render Service · PID 487162.3%1.8 GB

   Lumen Helper (GPU) · PID 481814.2%520 MB

   Lumen Helper (Renderer) · PID 48215.8%340 MB

   Lumen Cache Agent · PID 48361.4%180 MB

   Lumen Audio Bridge · PID 48400.3%60 MB

3. 03Step 3 of 9

   Step 3. Jump to a peak

   Under the strip, Largest peaks lists up to five. Click one. The playhead moves there, the sentence on the left changes to say which app was the largest at that moment, and a banner reminds you that you are looking at the past.

   You can also drag along the strip, or step one sample at a time with the arrows beside the slider.

   History

   Recent detailsSummariesWeekly reportSaved app historySearch or jump to…⌘KPauseRecord

   Inspecting a historical sample · 13 Oct 2026 at 10:31:06Return to Live

   Reviewing10:31:06

   96.8%

   Mac CPU100% = whole Mac

   Lumen Edit was the largest workload.

   At this moment it used 986.2% CPU across 9 processes, where 100% is one core.

   Pressure NormalThermal Fair

   Recent detailsEvery sample keeps its apps and process lifetimesMac CPU

   10:31:0612345

   100%50%0%

   10:12:2010:27:1910:42:18

   Previous sampleNext sampleSample 564 of 900 · 479 processes

   Click or drag to inspect the workloads at that time. Choose a workload below to see its resource history.Return to Live

   Largest peaksHighest Mac CPU samples in this window, at least 1m 29s apart · select one to move the playhead

   196.8%10:31:06257.1%10:32:40330.5%10:38:06427.8%10:17:06526.2%10:35:46

   Recent activitySaved sessions

   10:12:20 – 10:42:18 · 900 samples · 29m 58s retained

   Recent history updates on screen about every 5 seconds. The actual retained window is limited by time, samples, and process count.

   Average Mac CPU25.0%1,798 measured seconds

   Observed workloads2129 no longer present

   Average used memory21.2GBTime-weighted observed memory

   Workloads across this historyFind an app or executable

   Sorted by measured CPU-seconds. Exited apps remain available for inspection. A partial label means some process measurements are unavailable.

   WorkloadCPU-secondsAverage CPUPeak memory

   LLumen Edit9 lifetimes3,014.1167.6%9.4 GB

   PPixelroom4 lifetimes · exited806.4170.1%2.8 GB

   KKite Browser26 lifetimes · partial740.841.2%4.6 GB

   Kkernel_task1 lifetime406.322.6%2.4 GB

   FForge IDE14 lifetimes361.420.1%3.2 GB

   WWindowServer1 lifetime321.817.9%1.3 GB

   HHarbor9 lifetimes312.917.4%5.6 GB

   RRoundtable5 lifetimes172.69.6%940 MB

   212 of 212 workloads · 9 exited

   L

   Lumen Edit/Applications/Lumen Edit.app

   Show history forAll processes in this workload

   ResourceCPUGPU timeMemoryDisk readDisk writeReceivedSent

   CPU100% = one core

   1,000%500%0%

   10:12:2010:27:1910:42:18

   10:31:06 · CPU: 986.2%

   The axis is one core. A workload can pass 100%.

   Workload read: 3.4 GB in 1,798.0 measured secondsWorkload written: 11.2 GB in 1,798.0 measured seconds

   Processes at 10:31:06

   ProcessCPUMemory

   Lumen Render Service · PID 4871512.6%2.9 GB

   Lumen Encoder · PID 4874318.4%1.4 GB

   Lumen Edit · PID 481284.2%3.6 GB

   Lumen Media Reader · PID 483041.3%412 MB

   Lumen Helper (GPU) · PID 481818.9%486 MB

   Lumen Helper (Renderer) · PID 48217.6%298 MB

   Lumen Cache Agent · PID 48362.4%164 MB

   Lumen Audio Bridge · PID 48400.8%58 MB

   Lumen Update Agent · PID 48520.0%22 MB

4. 04Step 4 of 9

   Step 4. See who was busy then

   Below, Workloads across this history ranks apps by the processor time they used over the whole window. Apps that have since quit stay in the list, marked as exited. Select one to chart its CPU, GPU time, memory, disk or network over time on the right.

   History

   Recent detailsSummariesWeekly reportSaved app historySearch or jump to…⌘KPauseRecord

   Inspecting a historical sample · 13 Oct 2026 at 10:31:06Return to Live

   Recent activitySaved sessions

   10:12:20 – 10:42:18 · 900 samples · 29m 58s retained

   Recent history updates on screen about every 5 seconds. The actual retained window is limited by time, samples, and process count.

   Average Mac CPU25.0%1,798 measured seconds

   Observed workloads2129 no longer present

   Average used memory21.2GBTime-weighted observed memory

   Workloads across this historyFind an app or executable

   Sorted by measured CPU-seconds. Exited apps remain available for inspection. A partial label means some process measurements are unavailable.

   WorkloadCPU-secondsAverage CPUPeak memory

   LLumen Edit9 lifetimes3,014.1167.6%9.4 GB

   PPixelroom4 lifetimes · exited806.4170.1%2.8 GB

   KKite Browser26 lifetimes · partial740.841.2%4.6 GB

   Kkernel_task1 lifetime406.322.6%2.4 GB

   FForge IDE14 lifetimes361.420.1%3.2 GB

   WWindowServer1 lifetime321.817.9%1.3 GB

   HHarbor9 lifetimes312.917.4%5.6 GB

   RRoundtable5 lifetimes172.69.6%940 MB

   212 of 212 workloads · 9 exited

   L

   Lumen Edit/Applications/Lumen Edit.app

   Show history forAll processes in this workload

   ResourceCPUGPU timeMemoryDisk readDisk writeReceivedSent

   CPU100% = one core

   1,000%500%0%

   10:12:2010:27:1910:42:18

   10:31:06 · CPU: 986.2%

   The axis is one core. A workload can pass 100%.

   Workload read: 3.4 GB in 1,798.0 measured secondsWorkload written: 11.2 GB in 1,798.0 measured seconds

   Processes at 10:31:06

   ProcessCPUMemory

   Lumen Render Service · PID 4871512.6%2.9 GB

   Lumen Encoder · PID 4874318.4%1.4 GB

   Lumen Edit · PID 481284.2%3.6 GB

   Lumen Media Reader · PID 483041.3%412 MB

   Lumen Helper (GPU) · PID 481818.9%486 MB

   Lumen Helper (Renderer) · PID 48217.6%298 MB

   Lumen Cache Agent · PID 48362.4%164 MB

   Lumen Audio Bridge · PID 48400.8%58 MB

   Lumen Update Agent · PID 48520.0%22 MB

   Measured usage over timeCPU-seconds integrate measured CPU rates over their valid intervals. 100% for one second is one CPU-second. Averages cover measured intervals; missing values and gaps are excluded. Memory is sampled footprint, with resident fallback, and shared pages can overlap. Selected times also apply to the CPU, Memory, Disk, Network, and Processes pages.

5. 05Step 5 of 9

   Step 5. Days and months: switch to Summaries

   Click Summaries in the title bar. l/Activity saves a summary of the whole Mac every minute. Choose a range from Last 24 hours to 1 year, and a metric: CPU, GPU, Memory, Disk or Network. Time when the Mac was asleep or the app was closed stays a gap.

   History

   Recent detailsSummariesWeekly reportSaved app historySearch or jump to…⌘KPauseRecord

   Latest summary13 Oct 2026 at 10:41

   23.6%

   Mac CPU · summary average100% = whole Mac

   Summarized from 30 system samples.

   1-minute summary. System counters only; detailed app and process samples require a recording.

   Summary rangeLast 7 daysSummary metricCPUGPUMemoryDiskNetwork

   12345

   100%50%0%

   6 Oct, 10:429 Oct, 22:4213 Oct, 10:42

   Click or drag to inspect a summary. Missing measurements remain gaps.

   Largest peaksHighest CPU minutes in this range, at least 8h 24m apart · select one to move the playhead

   194.2%13 Oct, 10:31278.4%12 Oct, 16:07371.3%7 Oct, 15:12466.0%9 Oct, 11:48558.7%10 Oct, 16:24

   System history

   Measured summaries saved in /Users/sam/Library/Application Support/app.activity.desktop/Profile/History

   Average16.8%Weighted by measured time

   Peak summary94.2%13 Oct 2026 at 10:31

   Summaries with readings9,240of 9,240 summarized

   System samples277,200Captures summarized

   Summary averages cover measured intervals only. Full minutes cover thirty days, hourly summaries ninety days and daily summaries one year. Missing time remains a gap. Long-term summaries contain system counters; detailed app and process samples require a recording.

   Refresh summaries

6. 06Step 6 of 9

   Step 6. Per app, over days: turn on saved app history

   Summaries describe the Mac as a whole. To keep a record per app, open Settings (⌘,) → History & Recording, and in Saved app history set Retention to 7 days or more. It is off until you choose.

   SettingsMake l/Activity work the way you do.

   Search or jump to…⌘K

   Search settings

   GeneralDark · Dock and menu bar

   PermissionsFinder not checked

   MonitoringEvery 2 seconds

   History & Recording30 min live · 24 h max

   Storage & CacheEvery hour · 1.8 GB

   AlertsNotifications off

   About & PrivacyVersion 2.39

   Changes save automatically

   History & RecordingChoose how much activity to retain.

   Live historyRecent samples stay in memory until l/Activity quits

   Keep history for

   30 minutes

   System graphs · 29m 58s span · 900 samples

   Process details · 29m 58s span · 900 samples

   Shown in History · Recent detailsClear History

   System summariesLonger trends without saving every process sample

   Save system summaries

   Retention

   30 days

   Shown in History · System summaries and weekly reportsClear summaries…

   Saved app historyOptional, local resource aggregates

   Retention

   7 days

   Shown in History → Saved app historyClear saved app history…

   Session recordingsRecord a session to retain detailed readings after quitting

   3 saved sessions

   Maximum durationA recording stops after 24 hours

   24 hours

   Recording budget: 2 GiB1 to 8 GiB for each recording

   When a recording stopsRecordings stop when their duration or storage budget is reached. Saved sessions remain in ~/Library/Application Support/app.activity.desktop/Profile/Sessions.

   What l/Activity keepsConfigured maximum spans, on a log scale · actual live coverage appears above

   System graph historyIn memory · up to 30 minutes

   Lightweight system samples. Process details may cover a shorter span because of the memory cap. Both clear when l/Activity quits.

   Minute summariesOn disk · 30 days

   System averages and peaks for each minute, with gaps preserved.

   One session recordingOn disk · up to 24 hours

   Detailed readings while you record, up to 2 GiB. Saved sessions stay in Profile.

   1 min10 min1 h1 day30 days

7. 07Step 7 of 9

   Step 7. Read the per-app record

   From then on, History → Saved app history lists your apps with the heaviest first for the range you choose. Select one for its average, its peak and a chart.

   History

   Recent detailsSummariesWeekly reportSaved app historySearch or jump to…⌘KPauseRecord

   Saved app history

   Local resource summaries of apps and their helpers

   ResourceCPURange7 daysFind an app or executableRefresh

   Lumen Edit31.8%

   Kite Browser4.1%

   Forge IDE2.0%

   Harbor2.3%

   Roundtable1.2%

   PixelroomPartial coverage6.4%

   Northwind Sync0.5%

   Tessel Design0.9%

   Tempo Player0.3%

   Brightline Mail0.2%

   Atlas Maps0.4%

   Quill Notes0.1%

   Finder0.1%

   Previous1–13Next

   Lumen Edit/Applications/Lumen Edit.app

   Average31.8%Measured intervals

   Peak986.2%Observed reading

   Total176,299.2CPU-sRetained measurements

   6 Oct 2026 at 10:45 – 13 Oct 2026 at 10:41 · 554,400 measured seconds · 277,200 readings

   100% = one core

   1,000%500%0%

   6 Oct, 10:459 Oct, 22:4313 Oct, 10:41

   Full minutes cover the last 24 hours, 15-minute summaries the previous six days, hourly summaries through 90 days, and daily summaries through one year. Averages exclude gaps; lines break at missing intervals and interruptions. Activity within a summary is not reconstructed.

   CPU uses a per-core scale. GPU time can overlap across clients and is not device utilization or watts. Memory is sampled footprint with resident fallback; shared pages can overlap. Disk and network totals integrate valid observed intervals only. Partial GPU/network readings are lower bounds.

8. 08Step 8 of 9

   Step 8. A week on one page

   Weekly report → Prepare report sets last week beside the week before for CPU, GPU, memory, disk and network. App names are left out until you tick Include app names in this report. Export report… saves it as text.

   History

   Recent detailsSummariesWeekly reportSaved app historySearch or jump to…⌘KPauseRecord

   Weekly report

   A local review of the last complete Monday–Sunday week

   Earlier weekLater weekRefresh report

   5 Oct 2026 – 11 Oct 2026

   ResourceAveragePrevious weekMeasured coverageMac CPU14.2%12.9%154.0 h · 91.7% of weekDevice GPU9.8%8.1%153.6 h · 91.4% of weekUsed memory20.6 GB19.8 GB277,200 memory samplesDisk read1.9 MB/s2.3 MB/s154.0 h · 91.7% of weekDisk write3.1 MB/s2.6 MB/s154.0 h · 91.7% of weekNetwork received412 KB/s388 KB/s154.0 h · 91.7% of weekNetwork sent96 KB/s104 KB/s154.0 h · 91.7% of week

   9,240 retained summaries; largest bucket 1 minutes. Averages exclude missing time. App buckets crossing a week boundary are excluded. Comparisons reflect different measured coverage and do not establish a trend or cause.

   Include app names in this report

   Leading retained apps by measured CPU time (100% = one core):App 1: 162,439.2 CPU-s · 29.3% averageApp 2: 21,067.2 CPU-s · 3.8% averageApp 3: 9,979.2 CPU-s · 1.8% averageApp 4: 6,098.4 CPU-s · 2.2% averageApp 5: 3,880.8 CPU-s · 0.7% average

   Reports use retained readings only. Collection can be enabled in Settings → History.Export report…

9. 09Step 9 of 9

   Step 9. Come back to now

   Whenever you are looking at the past, Return to Live is in the banner under the title bar and beside the slider.