Word Riot is one of the most respected online journals of all time. They are also well established, they were first founded in 2002. Word Riot is known to publish edgy work by emerging poets and writers.
They publish flash fiction up to 1,000 words in length, and narrative fiction, short stories, novel excerpts, and essays that are up to 6,500 words. The interviews and reviews they publish are up to 4,000 words in length. There are no stated limits on the length of poems, but they want to see no more then 6 poems at a time in a single document.
Word Riot uses Submittable as their submission manager, and it is very easy to use. They generally respond to work within a week. They have a very low acceptance rate of well under 5%.
The work the editors at Word Riot favor is edgy, and stretches forms. They are interested in experimentation but they want the language to ultimately make sense.
Word Riot has other opportunities for writers beyond the online journal. They have begun to publish short story collections and chapbooks. They put a lot of energy into promoting these publications on their website but also by attracting famous reviewers like Johnathon Franzen to praise the books they are publishing.
Word Riot may be hard to get into, but it is worth the effort once they accept one of your pieces, as you will be published in one of the best known online journals out there. You can visit their website at: http://www.wordriot.org/wrp/baby.