For help unlocking the full version and connecting to Google Calendar please see the "Desktop Guide"

Video Instructions for Using GCalToolkit

Important Notes & FAQ

GCalToolkit is a very powerful tool, and should be used with caution: Please backup your Google calendar to iCal before you start (in Google Calendar "Settings" > "Calendars" > "Export"), and take the time to learn how GCalToolkit works before you use it on mission-critical calendars.

The Google Quota:Google Calendars has a daily (and maybe weekly) quota system that limits accounts to approximately 18,000 events downloaded/edited/deleted within a 24 hour period. Accounts with mass duplication issues will often hit this quota limit during faulty syncing and exhibit unusual behaviour such as slowness, problems creating new calendars, and problems exporting a backup as zipped iCal files (the surest sign of quota problems). The solution is to disable ALL syncing with Google Calendar (or simply change your Google Account password), and be patient. Google will usually reset your quota within 24 hours, at which time you should immediately create an iCal backup of your calendar data (regardless of duplicates), and then start cleaning up your Google Calendar with GCalToolkit as described on the rest of this website.

If you experience problems when using GCalToolkit on large calendars then please bear this in mind - if the problem persists please send me an email or use the contact page to get in touch, and include as much detail as possible about your situation.

Using GCalToolkit with other calendar software

If you use Outlook®, iCal, Sunbird or any smartphone (Android, iPhone, Blackberry...) that can sync to Google, then you can set up 2-way sync between your calendar and Google Calendars to take advantage of the power of GCalToolkit - this means that you can delete duplicates, mass edit, mass delete, search/replace, shift events, spreadsheet export etc. in nearly any calendar software using GCalToolkit. Please read the "Desktop Guide" for more information on the full editing power of GCalToolkit.

If you have an iCal (.ics) or .csv calendar file with duplicates that you need to remove, or multiple events that you need to delete, simply import the file into a blank Google Calendar, then use GCalToolkit to remove the duplicates, or edit/delete multiple events. When you are finished, export the result as a new iCal (.ics) file to be imported into whichever calendar software you use. If you use the Mac "Calendar" software formerly known as iCal... you can either export an iCal (*.ics) file and import it to Google Calendar for editing with GCalToolkit, or set up 2-way sync with Google Calendar instead.

For information on downloading and installing GCalToolkit please visit the Download page

Manage unlimited Google Calendars 

  • Free Trial: Download the desktop software

  • Full Version €19: 1 month licence and support

  • Full Version €29: 1 year licence, free updates and support

  • Full Version €59: LIFETIME* licence, free updates and support

  • Enterprise €99: As above + 10 installs, priority support and your own API Quota if required

  • Secure payment on PayPal - most Credit Cards accepted, no Paypal account needed

  • GCalToolkit runs on nearly any device: Windows, macOS and Linux

  • GCalToolkit works on any platform which supports Java (Windows XP only runs on version 1.3.6)

  • Unlimited help & technical support for all full version users

  • Help & advice  for any Google Calendar problem!

Full version licences are valid for one household on unlimited Google Calendars. The full version allows you to process all events on your Google Calendars.

Please keep your account details private: Google places a limit on the number of daily requests software such as this can perform, and the GCalToolkit server will detect multiple installations so abuse may result in account restrictions. For use within one household or by a single business user you may use a "Personal" licences - otherwise you should purchase an "Enterprise" license.

Please Note: If support requests exceed a certain limit I will have to remove the "Lifetime" licence

The trial allows you to process 500 events

(* i.e the lifetime of GCalToolkit)


New Features in version 2

GCalToolkit v2 has many fantastic new features to help you repair and maintain Google Calendars, such as Meet management, RRULE editing, Dark Mode, Modified date, in addition to the v1.x features such as mass color edits, fully customizable column views and spreadsheets, adding prefixes/suffixes, case sensitive filtering (and regex support), mass editing of busy/free status, mass editing of the "guests can modify" field, a "shift" events option in the "Copy/Move" menu to allow you to duplicate groups of events (such as a work shift) that do not lend themselves to regular repeat event rules... and many more improvements and additions to make calendar maintenance and repair with GCalToolkit easier and more powerful than ever before.


Q: What is the easiest way to delete all my Duplicates from Google Calendar and synced devices?

A: Install and run GCalToolkit, follow the simple steps to load your Google Calendar, check the number of duplicates detected, then click "Save" and wait. That's it!

Q: What does "Quota Restricted" mean?

A: Google Calendars has a mysterious quota system that limits accounts to approximately 18,000-20,000 events created/edited/deleted within a 24 hour period (although it is sometimes 9,000 events, and there may be weekly quotas too).  If you experience problems when using GCalToolkit on large calendars, especially if you have had syncing problems that created duplicates, then please bear this in mind. Quota is usually reset by Google every 24 hours, although some users with very large calendars (>20,000 events) and sync problems have sometimes had to wait up to 9 days for the quota to be reset... Symptoms of Quota problems include failed GCalToolkit downloads, failed deletes/edits, sluggish calendar behaviour in the browser, problems creating new calendars, problems "Exporting" Google calendars in "Settings" > "Calendars". 

if the problem persists please use the contact page to submit a support request, including as much detail as possible about your problem. 

Q: I can't even "Export" my calendars from Google Calendar Settings > Calendars!

A: This is the most sure sign of the quota problems described above - as you approach the quota limit, GCalToolkit may only be able to download parts of your calendar even though browser behaviour appears normal; if you are unable to "Export" in a browser then you have a serious quota problem - please contact me for information on who to contact, where to leave help requests, and exactly what to say.

Q: GCalToolkit is not working, and I do not think it is a Quota problem.

Please check that your firewall or other security software is not blocking GCalToolkit from accessing the internet, and that you have a stable internet connection. Office networks can be troublesome - in some cases you may have to ask your network administrator to modify the network settings to allow the Desktop version of GCalToolkit to work correctly.

Q: How do I delete all my Duplicates using the Desktop Software?

A:When you download a calendar all the duplicates are automatically marked "To Be Deleted" and will be colored red.  When you click the blue "Save" button all the duplicates that have been detected (within the events that you downloaded) will be deleted from Google. The total number of events, and the number of duplicates is displayed top right - and you can click "Preview Changes" to see a list of the duplicates that will be deleted before you Save.

If you change your mind and wish to restore the duplicates that you deleted, go to Google Calendar Trash and restore the events.

If your duplicates are not detected, please change the duplicate detection settings in the "Options" menu, "Duplicates" tab.  This allows you to relax the duplicate detection rules to include any events with only the same title & start time, for example. Sometimes you may have duplicates that are not detected because the repeat rule is formulated slightly differently by some syncing software, or there is an invisible space in the Location; this option lets you ignore these differences.


Q: My Calendar is not in Google Calendar - can I still use GCalToolkit to remove duplicates and edit my calendar?

A: Yes. If you are use Outlook®, iCal, Sunbird or any smartphone (such as iPhone, Blackberry or Droid) that can sync to Google, then set up 2-way sync between your calendar and Google Calendars to take advantage of the power of GCalToolkit - this means that you can delete duplicates, mass edit, mass delete, search/replace etc. in other calendar software using GCalToolkit as long as it will sync, or you can import the calendar to Google Calendar.  Please see Google Sync for more information on how to sync with Google Calendars.

Alternatively, if you have an iCal (.ics) or .csv calendar file with duplicates that you need to remove, or multiple events that you need to delete, simply import the file into a blank Google Calendar, then use GCalToolkit to remove the duplicates, or edit/delete multiple events.  When you are finished, export the result as a new iCal (.ics) file to be imported into whichever software you choose to use.


Q: Today I imported/synced another Calendar to Google and now my calendar is a complete mess! Can GCalToolkit help?

A: Yes!   GCalToolkit can filter events by the "Created" date/time to delete a specific Import/Sync (see "Delete Selected Events" below).  

For example, if a failed import attempt mixed two calendars together in a single Google Calendar, you can delete all events that were created by the failed import without affecting your pre-existing data, even if the dates and times are all mixed up together.  Or, if you sync another calendar to your Google Calendar and then need to delete data that has been mixed in with your existing data, simply load up your Google Calendar in GCalToolkit, and filter the events by "Created" date and click the "Delete Selected Events" button in GCalToolkit to mark all the highlighted events for deletion and then "Save". Hey presto! All events created during the last faulty sync/import will be deleted leaving all your previous data intact. Please note that the "Created" column refers to the date and time that an event was initially created in Google Calendars - only events that are created (not modified) during syncing, and any events created during an import, can be deleted in this way.


Q: I made changes to my Google Calendar using GCalToolkit Desktop Software, closed the program then went to Google Calendars in my browser and saw that I had made mistakes - what can I do?

A: You did make a backup before you started, didn't you? Some things can be reverted in GCalToolkit as long as you have not yet closed the program. For example, you can undo edits to Titles, Descriptions and Locations using "Set Original Texts" in the "Edit Selected Events" drop-down box. You can do the same with RRules, Guests, Colours, Privacy, Busy/Free etc. However, you cannot undo copy/move operations, or recreate Meets with the same Meet IDs.

Please note that if you have edited your Google Calendar manually in your browser since you used GCalToolkit to edit/delete then you may see unexpected results because GCalToolkit would be trying to work with an outdated copy of your calendar.

Q: I'm using the trial version of the Desktop Software to delete my duplicates - why can I still see some duplicates this month?

A: The trial version only downloads 500 events:  any repeat event from BEFORE this period will NOT display, and if these are duplicated then they will not be detected.  To be 100% sure that all your duplicates are removed, please purchase and unlock the full version. If you still have trouble, adjust the duplicate detection rules in the "Options" menu.

Q:  Can I change the order in which the events are listed in GCalToolkit?

A: Yes. You can click at the top of most columns to order the events - for the title, summary and location columns this will put the events in alphabetical order; click again to reverse the order. Under "Events" you can choose whether to display only all day events, only all day repeats, only singles, only timed singles... 


Q: I get an error message when trying to load my calendar.

A: Google Calendars servers are sometimes busy... so if you see ERROR 403 or 404 please wait a minute and try again.  If the problem persists for a few hours then you should check that you have a stable internet connection, and that nobody else is logged in and editing your Google Calendar account.  If that doesn't help, try another Google Calendar to see if that particular Google Calendar has a problem - you may have corrupt events or another issue that is preventing GCalToolkit from downloading that calendar. Please do not hesitate to contact me for help on the contact page, including as much detail as possible about your problem.


Q: How do I "Unlock" GCalToolkit Full Version?

A: First you need to register on this site (use "Login with Google" for the easiest registration option) and follow the payment instructions. All payments are made on Paypal for security reasons - but you do not need a PayPal account to purchase GCalToolkit; most credit cards are accepted too. Once your payment has cleared you can Unlock as follows:

1) Install and run GCalToolkit
2) Either fill in your details in the "Registration" window which shows every time you click "Fetch Events", or click "Options" in the Menu and open the "Licence" tab
3) Enter the Email and Invoice number that you received after payment.
4) Click "Save" and restart GCalToolkit.


Q: I registered, purchased and "Unlocked", but GCalToolkit is still in Trial Version. What should I do?

A: Please check your internet connection was active, and copy/paste your email address and invoice number. If that still does not work, please contact me on the "Contact" page for help with details of your system and any error messages.

Q: I purchased GCalToolkit but I would like a refund.

A: Please get in touch explaining exactly why you wish a refund.


Q: Will you communicate my email address to others?

A: Never. You may get the occasional update from me, nothing more. is not affiliated with or endorsed by Google Inc.
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