A typical conference might feature 8-12 main sessions in a single day. That's a lot of content for your audience to focus on in a short period of time. Whichever speaker gets the post-lunch slot has to work extra hard to keep people's attention! This format makes sense when you're paying a day rate at a venue, but online events afford you a ton more freedom when devising your schedule.
One option could be to livestream content in smaller chunks over several days or even weeks. Let's say you have 10 x 45-minute sessions — instead of running them one after another over a full Friday (which would take 7.5 hours, not including breaks), you could schedule them two at a time over five consecutive Thursday afternoon sessions, each lasting 1.5 hours.
There are advantages and disadvantages to this approach, of course. On the plus side, it's a smaller commitment each time so you can keep the energy higher, making it easier to keep folks' attention. You also spread out your own workload and can build on the experience each time. On the down side, it introduces more variables in relation to your audience's and collaborators' availability, as it can be easier to commit to a single long day than multiple shorter sessions. Also, if you're running a hybrid event with an in-person element, this may not be a practical solution for you.
You'll be best-placed to judge which approach is likely to work for your event, content and audience. The main point is simply to free yourself from thinking that an online event has to exactly mimic the way you would run a physical event.
In addition to timings, consider deviating from the formats you're used to, especially if some or all of the talks will be pre-recorded. A bunch of longer sessions makes sense for in-person events, where you likely have to pay speakers' travel, accommodation and fees. But, as the barrier to entry for online events tends to be lower, you may find you can showcase more people in the same amount of time. A punchy 15-minute talk can be way more impactful than a session three times as long. Follow it up with a live Q&A to mix things up.
Breaks are important. They give people a chance to look away from their screens, stretch their legs, grab a sandwich, and so on. But just because there isn't a formal session happening, that doesn't mean you can't have some form of entertainment going on. Here are some ideas we've seen work really well:
Hire a resident musician for the event, and play pre-recorded live performances of their songs during the breaks. It's like a mini concert for free in the middle of the event.
Run a live "cook-along" over a longer lunch break. Publish a list of ingredients for a simple recipe in the hub ahead of time so folks can stock up if the want to, and then have someone make the meal on camera while audience members follow along at home.
Lead a guided meditation or a fun stretch to help everyone feel refreshed.
Roll an outtakes reel or behind-the-scenes footage from the event.
Play an interactive game or host a short quiz where participants can respond in the chat. Bonus if you can offer to ship prizes to the winners.
Put up a riddle or brainteaser for your audience to try and solve, and provide the answer when you come back from break.
Show a timelapse of something fun, like a piece of digital art being created or a Lego set being built.
Livestream some gameplay.
You can probably think of way more ideas to inject fun and personality into your online event by breaking up the schedule. The main takeaway is that you're not limited to trying to replicate the experience of an in-person event. In fact, all the better if you try and do something totally different!