android GCM registration ID max length

Question

In Google Cloud Messaging, what is exactly the registration ID maximum length?

Solution 1

A google engineer said the registration ID can be up to 4K. Users have observed it is 255 characters.

Solution 2

i think i can help you out with this... i´m working with GCM this week, and my device´s registration ID looks like this:

APA91bHPRgkF3JUikC4ENAHEeMrd41Zxv3hVZjC9KtT8OvPVGJ-hQMRKRrZuJAEcl7B338qju59zJMjw2DELjzEvxwYv7hH5Ynpc1ODQ0aT4U4OFEeco8ohsN5PjL1iC2dNtk2BAokeMCg2ZXKqpc8FXKmhX94kIxQ

163 characters!

i hope this can help you out...

Solution 3

On iOS all my registration tokens look like this:

lhBV25_Znsk:APA91bHFM9nbX-s0py6-ktzgdpP_y85RahdL3OJ4LG4v-jT_9QY8ZbZH8uK-JNO_BDy75b6RfDT-v-j5W0FXIFTif72ckT3kqLNBDNWYSd5AhxYwdJi3Wqfdqqi-wL8F_k1nm2qUS3Ra

(152 chars)

Note the colon after 11 characters. Note also that it has the sequence "APA..." AFTER the colon, however you should use the whole registration token.

Solution 4

There's no official limit for GCM ID, the payload size is 4k when I am writing this. Although, it is safe to assume 255 for GCM ID according to this and the discussion before me.

If it is in database that you are asking the question for, I suggest that you use TEXT.

View more solutions

Comments

[Dahevos]

thanks, i decided to choose a varchar(250) for the moment (hope Google will not increase the regID over 250 char in time)

[VaroX]

yeah, i´d do that too... btw, this´ my first C2DM/GCM development... and i´m kinda stuck now... because my device seems to get the registrationID right... and i have a php based server, where a want to send a notification everytime an user adds any content... and this seems to be right as well!!!! BUT! i dont get any notification on my phone/emulator. I check the Google Api Console to see if is there any traffic report... but there´s no data at all!! i´m getting frustrated with this!! do you know something about it? thx!

[Dahevos]

check permission in your manifest file. Use thie script linked in my answer

[loeschg]

Mine is 183 characters - 4/19/2013

[Andrew Westberg - BCSH]

This answer is dangerous. Just saw a reg id come in at 205. Blew up in our DB which had a field size of 200. We'll be increasing to 4096.

[Andrew Westberg - BCSH]

My testing suggests that your package name length has an effect on the token size. If you're running into some tokens coming in longer than you have space in your DB, changing to a shorter package name can relieve the issue in some cases.

[Gaston Sanchez]

Right! there is no official limit on the device ID. I think a sane number could be 512. Although maximum length I've come until now is 205, who knows, it could increase.

[Henry Aloni]

Also here is the explanation why it is 4k : The max size for a registration_id is bounded by the max size for a cookie, which is 4K (4096 bytes). In practice, the tokens are going to be much smaller than that, but you shouldn't rely on this behavior going forward. From groups.google.com/forum/#!topic/android-c2dm/AUGlvmJPyMM

[user2387149]

I have the same problem and I'm wondering the same thing... has someone figured out this?

[Lukasz Czerwinski]

The reason GCM didn't work for me was that I uploaded wrong .p12 file to Google server. Make sure that you generate the right one.

[Magnus Smith]

In SQL Server it would be better to use VARCHAR(MAX) because TEXT is a right pain to work with.

[blackjack]

In my new register i got the GCM reg id as like this 0vfNE9qzu8:APA91bEzTKfWMbhyjF736xarAF3i5A2-o2jTHvBqRO3Z6OCdp‌​t5qLvIIi_VymvFVcUIMc‌​hDNUiknexOKGKkEI-zoR‌​TvbXAh3atMPYoh2ROmk3‌​fifrnpH-GWP-a5PYr861‌​Qf6u5jY9uTP

[Rakib]

but what about another guy saying "255 is perferct with varchar. 4k is for the payload, not the reg id." later in the comment? groups.google.com/forum/#!msg/android-gcm/q2PzJTP71TY/…

[alicanbatur]

Do you use GCM for ios?

[naXa stands with Ukraine]

Reading on the same google group post, it seems it was a mistake, 4k is the limit for the payload of the message, not the reg id.

[greatvovan]

APA is an Android token, not iOS.