Why Progress Bars Don't Move Smoothly ▓▓▓░░░░░░

4 minutes remaining. Then 15 seconds. Then 5 hours. Why can't computers just tell you how long something's going to take? • MORE BASICS: uznick.info/border/PL96C35uN7xGLLeET0dOWaKHkAlPsrkcha
Written with Sean Elliott SeanMElliott/ • Graphics by William Marler wmad.co.uk
I'm at tomscott.com
on Twitter at tomscott
on Facebook at tomscott
and on Instagram as tomscottgo


  1. Tom Scott

    Tom ScottOy oldin

    I'm having to film back in the Tiny Room against green-screen again, as lockdown means the Centre for Computing History is closed! Hopefully they'll be open again soon, although that depends on a very different kind of progress...

  2. Culiynl

    Culiynl20 kun oldin


  3. RanMind YT

    RanMind YT20 kun oldin

    why do you private your videos before you upload them

  4. Michael Conroy

    Michael Conroy26 kun oldin

    How did you put in the time estimate of this video in the script as you were recoring? I slowed down the video speed to .25 but can't see where you may have stitched two takes together.

  5. NoobKing

    NoobKingOy oldin


  6. PrxjectMeme

    PrxjectMemeOy oldin

    Why does my phone tell me that this comment was posted before the video was?

  7. szubert - max

    szubert - max14 soat oldin

    1:57 maybe 4 different loading bars? For each process?

  8. Philippe Futureboy

    Philippe Futureboy22 soat oldin

    I didn’t expect that Tom Scott.exe could be rebooted. The more you know 🌟

  9. theawesomness07

    theawesomness07Kun oldin

    Among Us downloading task be like: Estimated time: 4 days *2 seconds later* Estimated time: 6 seconds

  10. Christoph Southwell

    Christoph SouthwellKun oldin

    Gosh Tom, call me out why don't you!

  11. ike

    ikeKun oldin

    I like to combine the speed in rate of transfer or time remaining while also having my harddrive light & CPU task manager to see which is bottle-necking at what point. This is a form of entertainment I guess

  12. flex

    flex2 kun oldin

    I love the bars that stop at 100% for 10 minutes or so

  13. Paulo Lukeny

    Paulo Lukeny3 kun oldin

    What is this golden piece of chanel that just dropped on my recommendations, SUBBED!

  14. Windows 10X

    Windows 10X3 kun oldin

    It’s actually placebo its jus randomly stoping at random intervals and thats why it stops at 99% cuz it’s actually at 70% or 50% or maybe even 30%

  15. SuperPlayer56 Gaming

    SuperPlayer56 Gaming3 kun oldin

    Things to do do, to make progress bar faster: Buy an ssd Upgrade ram (and probably buy more ram than you have on a computer) Buy better proccesor Buy better router/modem and get faster internet Buy faster hdd(s) Install linux Congratulations!!! Your game/program now loads/downloads/installs faster!

  16. dick harambe

    dick harambe3 kun oldin

    Working on updates 2% complete 1 hour later Working on updates 10% complete Working on updates 100% complete

  17. Ruelle Heroux

    Ruelle Heroux4 kun oldin

    Can i express how perfectly aligned the timer is in video to the UZnick timer?

  18. ProHolmes

    ProHolmes4 kun oldin

    I just like windows' there are 7 years left for finish copying your files. While showing me the speed and amount of data left, which definitely won't be 7 years if i divide data amount by speed.

  19. shmo247

    shmo2474 kun oldin

    Modern warfare updates: 1%.......2%.........not enough storage delete 148gb of data

  20. Thot Slayer 420

    Thot Slayer 4205 kun oldin

    what about a 2D progress block, width for data (so maybe mb or gb) and height for file count, never seen one, just thought of it

  21. kalle anka

    kalle anka6 kun oldin

    Best solution would be to put a title to every segemt of the progress bar. Anyone who watches porn on the hub will have found this out. If you dont care about foreplay you know exactly on te second to skip to, to skip that part. So for a progress bar for a install. Just title the segement so that we know what part the computer is working on and we know what we might think of upgrading

  22. RamennBowls

    RamennBowls6 kun oldin

    "The most important job is to reassure that yes, things are happening, progress it being made" That moment when the progress bar is stuck at 99% for about 28 minutes...

  23. Reese606

    Reese6067 kun oldin

    The only accurate progress bar is the 3DS one And no, not the blue one The one when your digitally downloading a game off of the eShop

  24. Ask Master

    Ask Master7 kun oldin

    100% ... Restarting... 30% .... ... .. 58% ............... 79% ................ 100% .................................................................... Aaaaand it crashed

  25. Adam Cogley

    Adam Cogley7 kun oldin


  26. gunship sequel budyboy

    gunship sequel budyboy7 kun oldin

    you should create a program that changes the line on the video

  27. YaBoy •

    YaBoy •7 kun oldin

    Putting my finger over the progress bar to see if its moving

  28. Vex989

    Vex9898 kun oldin

    Steam installing a game be like: 1 minute left -- 2 hours left -- 5 days left -- 6 minutes left

  29. agustinbs

    agustinbs9 kun oldin

    Are you reporting from 1998?

  30. DG Secret

    DG Secret9 kun oldin

    Tom Scott : Why Progress Bars Don't Move Smoothly Me : Wondering why the progress bar on the title doesn't move

  31. Peto

    Peto9 kun oldin


  32. KoGa

    KoGa10 kun oldin

    "Why can't computers just tell me how long something is going to take?" Because progress bars don't show you time... they show (suprise!) progress.

  33. Rory M

    Rory M10 kun oldin

    Shout out to those 99 years that I was told it was gonna take for my game to open when I was 8.

  34. P Church

    P Church10 kun oldin

    This is why I leave and do something else when I’m downloading something. If it takes 5 minutes or 2 hours I’ll have something nice to come back to once I remember

  35. GigaGame

    GigaGame10 kun oldin

    who needs a progress bar when u have a gaming fridge that can download anything almost instantaneously


    YY YELLOW10 kun oldin

    Why this guy is soo much underrated

  37. karehaqt

    karehaqt10 kun oldin

    Good old Microsoft Minutes

  38. Deconimus

    Deconimus11 kun oldin

    How was the halting problem not mentioned in this video?

  39. KysterPSY

    KysterPSY11 kun oldin

    Loved the Sopranos kinda ending.

  40. Pat Smash

    Pat Smash12 kun oldin

    My loading bar just goes backwards

  41. Chane

    Chane14 kun oldin

    looking at you STEAM

  42. A Skellington

    A Skellington14 kun oldin


  43. Yajihba

    Yajihba14 kun oldin

    Someone tell computer making people to put this when turning on a computer after shutting it down

  44. Lordlouckster

    Lordlouckster15 kun oldin

    Solution: Have individual progress bars for each step. Step 1/4: 10% Step 1/4: 20% ... Step 1/4: 100% Step 2/4: 10% Step 2/4: 20% ... Step 4/4: 90% Step 4/4: Done!

  45. Hasan A

    Hasan A15 kun oldin

    The one thing I wish I could do when it came to downloading something is allocate as much resources to downloading as possible. I love that you can still Watch Netflix, have a conference call, and edit a video in Adobe After affects, while downloading somthing, but sometimes I just want to download something, walk away and have the computer just worry about downloading or moving the file.

  46. Sideways

    Sideways15 kun oldin

    This is the corollary to Windows 10 offering to kill any app that takes more than 15 seconds to do something - apparently Windows isn’t seeing a progress bar😅

  47. Eeee

    Eeee15 kun oldin

    Bar: 1% to 99% : 20 minutes Bar: 99% to 100% : *10 hours*

  48. Viktória Vadon

    Viktória Vadon16 kun oldin

    I agree, as long as the progress bar is moving (and not backwards!), I know something is happening!

  49. Frog 4096

    Frog 409616 kun oldin

    3:42 Looking at you, Windows 10

  50. Samson Kinyanjui

    Samson Kinyanjui16 kun oldin

    /////// / / / / / / / / / / / / / 10more years ///////// / / / / / / / / / / / 30more seconds

  51. Riley Carpenter

    Riley Carpenter17 kun oldin


  52. mozl83

    mozl8317 kun oldin

    That's also why many programmers have gone the other way and just show "progress indicator" instead of progress bars. Like the spinning wheel on Windows. It just shows that the PC didn't freeze and is still working, but you don't have any indication on how long it's going to take. Also if "time" isn't a parameter itself then the progress bar can never be give you a proper "remaining time". A countdown is always accurate because the time itself is the parameter that makes it work. Filetransfer ist based on the files and not on the time, so it will finish when it is finished, not when a certain amount of seconds have passed (like the queue in the supermarket. Fewer people doesn't mean the line is faster. There are just fewer people in front of you.).

  53. Cameron Figgins

    Cameron Figgins17 kun oldin

    Minecraft’s progress bar be like: And I took that personally

  54. Zari Hanssen

    Zari Hanssen17 kun oldin

    Loading time estimates be like: 20 minutes 4 seconds 45 minutes 5 minutes 999999 hours

  55. Butter of Sorrow

    Butter of Sorrow18 kun oldin

    Personally I like loading screens that tell you what exactly they're doing, like most source and goldsource engine games. "Validating game resources." "Sending client info." That kind of thing.

  56. French Comprehensible Input

    French Comprehensible Input18 kun oldin

    100% done = 90% done *Adobe Premiere users* will understand 😂

  57. Helio Gonzalez

    Helio Gonzalez18 kun oldin


  58. Silksong Date

    Silksong Date18 kun oldin

    4:48 smh now you'll have to record everything from the start rippppp

  59. SoftBunnyCreations Vibing

    SoftBunnyCreations Vibing19 kun oldin


  60. pencilchat

    pencilchat19 kun oldin

    my monitor froze during a download once, so i thought it took 4 hours to get a 20mb download done.

  61. Zoltan

    Zoltan19 kun oldin

    ▓▓▓▓▓▓▓▓▓▓▓▓▓▓░ 94%

  62. Eugene Lo

    Eugene Lo19 kun oldin

    Imagine the progress bar in the title is how long Tom Scott's life is

  63. Cypress

    Cypress19 kun oldin

    is this the guy who says “xnyopit”

  64. fossar _

    fossar _19 kun oldin

    Is it just me or was the audio an video out of sync (I'm assuming deliberately)? If so nice choice.

  65. Tomáš Lipták

    Tomáš Lipták20 kun oldin

    I think the best loading screens are when there are actually two (think winrar) one for the whole process and the other for individual processes. From there you can see that it is actually doing something.

  66. youtubeusername

    youtubeusername20 kun oldin

    Pov: you kept checking your scroll bar through out the video

  67. The cheese

    The cheese20 kun oldin

    Me when I tilt my phone facing down and the progress bars start moving again.

  68. Pawit Ninnabodee

    Pawit Ninnabodee20 kun oldin

    The absent water posteriorly impress because lion constitutively polish worth a hapless priest. determined, rotten kite

  69. RanMind YT

    RanMind YT20 kun oldin

    What is the 1% that’s taking so long to load

  70. wozerD

    wozerD20 kun oldin


  71. Leo Telles

    Leo Telles20 kun oldin

    You look young and old at the same time. That's a real mistyr to me, you should make a video about it!

  72. AK Nephtali

    AK Nephtali20 kun oldin

    The worst thing is when it goes to 99% immediately and then stays there for what feels like a millennium. Thank you for explaining this in your usual awesome way!

  73. SYS

    SYS20 kun oldin

    A thing the program could do to resolve, or at least find a more smooth load, is by logging the time, taking the estimated time that it took, and telling you that number. If it was a game, it could show how long it had taken the last 10 times, (assuming you would've loaded it that many times), and let's say a file upload, it could track how long it would take for 100 files, and estimate the amount of time, that this would take because its 10x times larger, or half the size = it would be 10 times longer or ½ times faster.

  74. BlurryPirate

    BlurryPirate20 kun oldin


  75. Phill Wainewright

    Phill Wainewright20 kun oldin

    Dropbox "Time Remaining" when uploading a video is a complete work of fiction.

  76. Stipe Poljak

    Stipe Poljak21 kun oldin

    Intro music from the Chase?

  77. HowDeeDoo

    HowDeeDoo21 kun oldin

    Steam update estimation times. 3 minutes, 7 minutes, 18 minutes, 2 hours, 17 hours... 12 seconds.

  78. whadup

    whadup21 kun oldin

    I cant be the only one that was annoyed that the two progress bars didn't match perfectly 😁

  79. Kebbo

    Kebbo21 kun oldin


  80. John Southfield

    John Southfield22 kun oldin

    The gaudy grip monthly hand because relish spectacularly apologise through a private cost. watery, pricey continent

  81. Lambor_ghini

    Lambor_ghini22 kun oldin

    Progress screens can lock up and fool you to wait forever but ultimately you have to reset the computer..

  82. Bubba Games

    Bubba Games22 kun oldin

    The video progress bar is half a second off

  83. Haydenex

    Haydenex22 kun oldin

    Loading Comment ■■■■□□□□

  84. Zak Fallows

    Zak Fallows22 kun oldin

    I have four letters for you: RTOS. A Real Time Operating System (RTOS) provides hard or soft guarantees of how long a program will take, in instruction cycles. Sometimes this is critically important, for instance if the machine is doing quantitative chemistry and it needs to error out if the reaction time wasn't very close to 90 seconds. It's fun stuff.

  85. Cristian Martinez

    Cristian Martinez22 kun oldin

    why a linguistic knows computing, that aint fair

  86. Paul Potter

    Paul Potter22 kun oldin

    Who else checked that the video progress bar was in sync?

  87. jeremiaas15

    jeremiaas1522 kun oldin

    What I'd like to know is, how is it possible that progress bars always show, even if for a split second, 100%. Surely, if that were truth, the next thing would pop up instead.

  88. LRC

    LRC22 kun oldin

    I love it when a simple download says "2 years remaining" or "∞ time remaining".

  89. AsrithTechsys

    AsrithTechsys22 kun oldin

    Are you anyway realated to Linus Torvalds?

  90. TROVEN

    TROVEN22 kun oldin

    Who else leave cursor at the edge of the progress bar to see if its actually moving?

  91. Sara Olmstead

    Sara Olmstead22 kun oldin

    The ugliest geranium invariably retire because client fortuitously muddle round a unbecoming hyena. oceanic, assorted oxygen

  92. Thaer Razeq

    Thaer Razeq23 kun oldin

    Always, stuck at the dreaded 99% or 100% more so than the previous 98% or 99% combined.

  93. Craig Smith

    Craig Smith23 kun oldin

    Large cache SSD and a modern high core CPU like Ryzen 9 or 10+ core i9. RIP, progress bar existence

  94. Abhinav Dev

    Abhinav Dev23 kun oldin

    When they do move smoothly It is the most satisfying thing in this world.

  95. Simon T

    Simon T23 kun oldin

    This is a repost?

  96. Snowjix

    Snowjix23 kun oldin

    3:42 Too real Tom..

  97. HP Gummy

    HP Gummy23 kun oldin

    I didn't need to know this

  98. Ariel Zabihi

    Ariel Zabihi24 kun oldin

    Do one on browser compilers and header data

  99. DoubleDS9

    DoubleDS924 kun oldin

    Excellent! Thank you.

  100. Cj Slime

    Cj Slime24 kun oldin

    I can understand why they change but the lock at 99.9 percent complete is annoying

  101. Phung Ngoc Quynh

    Phung Ngoc Quynh24 kun oldin

    The big decade virtually reject because polish fortunately bounce around a onerous sycamore. rampant, defeated sunday

  102. Shakhzod Mukhammadiev

    Shakhzod Mukhammadiev24 kun oldin

    *Good ol' floppy drives "3%.... 4%.... 98% DONE"*

  103. Candy Vargas

    Candy Vargas24 kun oldin

    The dramatic mother undeniably scare because coat wailly prepare in a second owner. sincere, elegant police

  104. Dino Hall

    Dino Hall21 kun oldin

    Am I supposed to know what this means?

  105. Hayato Tenryuu

    Hayato Tenryuu24 kun oldin

    Maybe Windows just decides to restart itself in order to install an update that I don't care about, and would actually rather I didn't have to have.

  106. Brando Calrisian

    Brando Calrisian24 kun oldin

    Beware the perfectly smooth progress bar, got it. Great advice, thanks, i had no idea about any of this!