iPhone 3G Slow After iOS 4.0 Update

A number of iPhone 3G users have experienced a significant degradation in performance after the iOS 4.0 update. iPhone 3GS users generally report across-the-board performance improvements with the new update, but original iPhone 3G users have reported slow app launching, delayed reactions to taps, and generally poor interface responsiveness.


Perform a “hard reset.” Hold down the sleep/wake and home buttons simultaneously for roughly 15-20 seconds, until the screen powers off then an Apple logo appears, which signifies a reboot. Some users have (oddly enough) reported that performing two hard resets resolves the slowness issue.

Restore, but not from backup. It appears that bad holdover data from iPhone backups can cause performance problems. Restoring as a new phone will delete contacts and other data, but may resolve this issue.

To do so, connect your iPhone or iPod touch to your computer, click “Restore” in iTunes, then choose “setup as new phone.”

Free up space. Make sure that your iPhone has at least 10% of its available memory free. OS X-based systems, such as iOS 4.0, may require some free space to operate properly.

Close open Safari windows. One iOS application that consumes memory in the background is Safari. Close all unused windows in the application by pressing the page switch button in the lower right portion of the screen then clicking the X at the top left of each page. See this page for screenshots.

Turn off Spotlight. Navigate to Settings -> General -> Home Button -> Spotlight Search and turn off all the options by tapping each one. Next, perform a hard reset by holding down the sleep/wake and home buttons simultaneously for roughly 15-20 seconds, until the screen powers off then an Apple logo appears, which signifies a reboot.

You can experiment with turning off only some options, but most users only report a meaningful speed boost if all options are turned off.

Turn off MMS. Navigate to Settings > Messages > MMS messaging and slide MMS Messaging to “Off,” then perform a hard reset as described above.

DFU Restore. A tedious process, but one that has yielded dramatic performance improvements for some users.

To perform a DFU restore, follow these steps:

1. Backup your phone and preserve data. Follow the steps in this Apple Knowledge Base article to transfer your purchases and backup your iPhone.

2. Put iPhone into DFU mode. Connect your iPhone to your computer and open iTunes (if it doesn’t open automatically). Hold down both the top (sleep/wake) and home buttons for exactly 10 seconds, then release the top (sleep/wake) button but keep holding the home button until  iTunes displays a message stating that a phone in recovery mode has been discovered.

3. Restore. Press the restore button and allow the phone to complete the restoration data. After it is done, select setup as a new phone.

4. Restore your backup (optional). Next, you can restore the phone again in the normal fashion (not DFU mode) using the most recent backup rather than setting up as a new phone. However, this may cause the original problem to return in some cases. If the problem returns, follow steps 1-3 again and do not restore your backup.

Feedback? info@appletoolbox.com.


  1. says

    Eve – I completely agree with you. Those are the exact words I would have written. I have since updated Vista to Win 7 and there is a night and day difference. Once my contract on my iPhone runs out I will never purchase another Apple product; even the iPod sucks. Try a Zune people.

  2. says

    SOLUTION: I worked out how to speed up the 3GS

    Step 1 – Submerge the iPhone in a bucket of Water
    Step 2 – Purchase the HTC Desire – Android OS

    Following these steps will dramatically improve your phone experience and will ensure your comments are inserted in Apples core!!

    • Wendi says

      What’s the Spotlight? My phone has gotten worse and worse!! Today I almost threw it against the wall at school just to see if it would work better after.
      Also Two Resets? Please explain

  3. says

    I had the same problems, did the reboot twice (holding the home and sleep/wake buttons) deleted the spotlight thingys, getting rid of unused apps ( i now currently have about 5) deleting all the safari windows open, turning mms off and phone is STILL slow. slightly better (very, very slightly) but the big thing is still the messages taking ages to open and keyboard taking ages to catch up. so not happy :(

  4. says

    I hate this upgrade! Sometimes, I can’t even answer the phone! (The response to my attempt to slide the lever over is so delayed that the phone call has gone to voice mail before I can get it to answer.) ARRRRRGGGGHHHHH!!!

    I will definitely try your suggestions, though, and truly appreciate your efforts!!!

  5. says

    iPod Touch 3G’s Calendar slow down terribly after
    installing iTunes 10 and iOs 4. This problem was resolved in my
    case by itself after upgrading by iOS 4.2.1 and synchronizing with
    MS Outlook and back up 2 times right each other. After 1st time
    sync. and back up the slow downs remained and after the 2nd
    synchronization and back up slow down has gone. During the
    synchronization there was time conflict between iPod and outlook
    which resolved by selecting iPod as reference source. My impression
    was that the slow dawn might come up when the synchronization is
    not fully done (e.g. when timing conflict remained, not resolved
    between outlook and iPod) between outlook and iPod.

  6. says

    Do not update.
    The best free tip I can give.
    The phone and the update will not work completely and it will not do so in the future. It´s planned obsolescence and part of Apple´s plan to sell new models.
    Until you read it as a scoop in the papers or find a document on Wikileaks it will be the dark secret of the staff at Apple.

  7. says

    Don’t buy an iphone I did my update 2 weeks after warranty period was up, as soon as the update was installed my touch screen didn’t work, texting was very slow or not at all, the screen was unresponsive or magnified and the slider did not work so I couldn’t answer calls, I tried to restore settings, did numerous back ups, even factory restore, about 15 times in total, held buttons down for resets everything, lost all my contacts, apps, photos, the lot! Apple are denying there is a problem with the update but i can see here there is, they don’t care. I have another year on this contract with a phone that doesn’t work my only option is to pay $249 for a 2nd hand replacement phone that only has 3 months warranty – i’ve been JIPPED! Very unhappy.

  8. Md.moinul kabir says

    phone 3G setting option open slowly its terrible…it takes 10 sec to open. what to do..can i back to previous version and how? pls help me out…i already did the spotlight matter and hard reset…bt it looks same.

  9. Md.moinul kabir says

    its i phone 3G version 4. setting option open slowly its terrible…it takes 10 sec to open. what to do..can i back to previous version and how? pls help me out…i already did the spotlight matter and hard reset…bt it looks same.

  10. i(NOT)Phone says

    I know what you can do as well as apple knows…since they have discontinued the updates for 3g rendering a 2 year smart dumbphone as usefull as a brick, you can spend another 700 euros (for us – the rich europeans) to buy an iphone4…and probably after an other 1,5 year that will be absolete as well so can get an iphone5 or 6 or 7…and so on…

    Thank you cr-apple

  11. DestreyDavis says

    ummm what if you’re FOURTEEN and your a textaholic? wait wait… MMS? how do you even turn that off?>

  12. DR GANDHI says

    I stay in India and had bought a iphone 3 g a year ago

    Love your article that i have pasted below and was very useful

    I HAD AFEW BASIC questions

    1 what software version can doTHE copy and paste function?

    2 also which is the ideal higest perfomance version for a iphone 3g?

    3 if i downgrade from version 4 to version 3.1.3 on my iphone 3g can i restore back my contacts , messages and emails




  13. WatcherDearie says

    Okay wow, I get some features need to be turned off for overall performance, but I’ve already turned off everything possible. Why is it that my iPhone 3G has to suffer such a slow response time and experience with almost everything off, while my sister’s iTouch is completely fast with over 100 apps, wifi on, and several other features on?

    I already tried everything above and it just turned out to be a waste of time trying.

  14. Jacob says

    Hi I bought a iphone 3gs a month back, I would say . its one of the best phone
    HTC and Android is just a trash. every game in Adroid runs very slow. Iphone gives the best experiance. I dont know why you all have a poor experiance

  15. pervertt says

    Thank goodness for your advice. I have a 3G phone. Turning off spotlight did nothing to help. Only the hard reset did the trick – it is now back to its usual quick speed.

  16. says

    An interesting dialogue is worth comment. I believe that you should write extra on this matter, it may not be a taboo topic however typically people are not enough to talk on such topics. To the next. Cheers

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