The Austrian part of Austria-Hungary had full male suffrage and rather generous self-rule and the right of schooling in your own language etc. The Poles of Galizia were experiencing quite a revival, both economically and culturally at the time and seemed to host no animosity to the Austrians.
The Austrians could probably offer the same arrangement to the Slovaks, Romanians, Serbs and Croatians within the Hungarian part of the Empire. Combined with an offer of land reform and suffrage for the Hungarian commoners, I think they could crush the revolt rather quickly - parts of the Honved will make a stand and it will probably cost a lot of lives, but unless foreign powers intervene, I do not think the Austrians will have any problems crushing the Hungarian revolt - and look like the good guys doing it (coming with freedom of language, suffrage, land reform etc).
The Hungarians will probably have very little support. The Serbs became an international pariah when they killed their royal family in a coup - only Russia would really deal with them after that. The Hungarians have killed an Austrian royal and rose in nationalist revolt. The Russians will not want to deal with that - they did after all support the Austrians heavily in 1848 - nationalist revolts carry some dire consequences for them as well. The French have nothing against the Austrians really, they got beef with the Germans but this is no causus belli for them. Likewise the British. The Italians would probably want to try to use the oppurtunity, but they failed 1866 and without Germany distracted elsewhere, I don't think they'll be so stupid that they try to go after two Great Powers at the same time.
So Austria-Hungary gets to deal with its own mess, with German support, and becomes the Federated Empire of Austria-Hungary-Slavonia in the process.
At the time before ww1, Russia had the higherst growth in %, but Austria-Hungary was close and grew more in raw numbers (since they grew from a higher level). If there's no ww1, it is quite possible that radio, railroad, roads, industry and economical development cements the Empire - while some nationalists want to get out, most see the benefits of being in a thriving country with most of the freedoms they want and a decent army to protect them.