Fastest Firemaking XP in Runescape (OSRS)

Method #1:
GE Firemaking Video:

Xp/Hr: ~520k/hr
Description: Use tinderbox on log with noted logs in your inventory to rebank without losing ticks.

Note that it is feasible to be cooking karambwans at the same time, albeit with higher click intensity.

Method #2:
Poh tele wintertodt

Xp/Hr: 320k (up to 385k if burning logs between games)

Description: Take 2 brews with you and stay inside the todt until you get long enough respawn time to drink reju pool and bank for fresh brews. Can fletch darts in between shorter respawn times. Burn redwood logs on your way inside after banking for increased xp rates. Fletch enough logs to hit 500 points if you would otherwise not get it due to excessive afking or starting the round late. Walk out of the way when you see heavy snowfall above the brazier and spam click it after to repair & relight. Keep your redemption prayer active at all times and toggle it back on after drinking rejuvenation pool if it has activated since the last pool.