android GCM registration ID max length

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

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

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...

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.