Is it possible to jailbreak my IOS 6.1.3 IPhone 4 for free?

Is it possible to jailbreak my IOS 6.1.3 IPhone 4 for free?

Yes it is, but it would be a tethered jailbreak, this means it cant turn on without it being connected to the computer, i recommend downgrading to 6.1.2 and get an untethered jailbreak for it to be more convinient. And all jailbreaks are free, if theyre asking for money its a scam. For the 6.1.2 jailbreak go to www.evasi0n.com

Yes you can, I unlocked mine here and yes it's free iphonegeeks.us/JB