This article gives you information about visa's when traveling to Indonesia. If you don't want to apply for a visa at an Indonesian embassy and you are only here for a short stay, then you have two choices upon arrival in Indonesia:
Number 1 is a $ 35 visa on arrival that is valid for 30 days and extendable in every immigration office throughout Indonesia for another 30 days. This visa is for all purposes, the only thing you can't do on this visa is work. In total with extension it means you can stay in Indonesia for 60 days before you have to leave the country. You can easily leave the country to a nearby foreign destination like Kuala Lumpur or Singapore and return the same day to get another visa on arrival.
The other option is choosing a free of charge tourist visa. This one is valid for 30 days only and is not extendable. It can only be used for tourist purposes.
If you are opting to stay for a longer time you have another two options:
Number 1 is applying for a tourist visa at any Indonesian embassy. This will give you 60 days upon arrival and is extendable 4 times for 30 extra days each. For the extension you will need a local sponsor from that area. So if you are applying for an extension at the Mataram Lombok immigration office you will need a sponsor that is from the island of Lombok. Maybe you want to travel further and land up in Medan Sumatra, you will do your next extension over there. It means you need to find another sponsor from that area to apply for your extension at the immigration office in Medan. In total this tourist visa can give you a 6 months stay in Indonesia if you can find or have a sponsor. Note: To apply for this visa in the first place you don't need a sponsor, only for the extensions. Look for all the exact requirements on the website of the Indonesian embassy you want to apply. Most embassies have there own requirements.
Number 2 is applying for a Social Budaya visa at any Indonesian embassy. Social Budaya stands for social visit visa and is meant for people who are visiting family ,or students that want to study in Indonesia. Lots of people that live in Indonesia for a short time use this visa. For the Social Budaya you already need a sponsor before applying at the Indonesian embassy. This same sponsor needs to sponsor you for all your extensions, it cannot be someone else. You can do 4 extensions each valid for 30 days. This means that in total you are able to stay for 6 months on this visa.
* note the sponsor always needs to be an Indonesian citizen or a foreigner that has KITAS (limited residence) or KITAP (permanent residence).
Please comment if you have questions or tell us about your experience.