literally almost every episode

Heavy use of strobe effect! S1E1: Fluorescent lights start flashing during a fight scene (51:00-53:00). S1E2: Harsh flashing fluorescent lights and police sirens (10:30-14:30). Machine guns create strobe effect in the dark (49:30-51:30). S1E4: White strobe (23:40-24:05). Short but bright flashing blue light (50:54-50:57). S1E5: Harsh strobe lights (18:45-19:25). S1E6: Short but bright flashing blue light (54:50-55:00). S1E7: Red/blue strobe lights (29:08-32:36, 39:50-40:40). S1E8: Fast but fairly dim strobe (23:06-24:00). S1E9: Fluorescent lights flash with varying speed and intensity (30:55-33:58, 37:16-37:26, 37:58-38:06, 40:20-43:25). S1E10: White strobe with increasing intensity (3:18-3:38). Two major fight scenes (26:35-27:52, 35:50-37:57). Harsh blue strobe (44:00-45:25). S2E8: One quick flash followed by white strobe (37:20-38:00). Harsh white strobe that intensifies quickly (42:40-end of episode).

When the kid goes in the library basement, there's strobe effects of the lights.

Alot throughout

There are a lot of gifs with bright, flashing colors, and many of the animations have them as well. There is a way around it, though- the Accessible Homestuck Project (accessiblehomestuckproject.tumblr.com) has image descriptions for most of the comic right now (and hopefully will be all of it, eventually), so you can know exactly what's going on without being exposed to strobes.

Apart from the main film, the very beginning's logo flashes are similar to a strobe effect. It's the only bit of the film that triggered my migraines, which strobe lights usually do.

Not exactly strobe but flashing lights

Light going on and off frequently on the subway while going through tunnels

Times are HH:MM(:SS), and approximate, but close. If prone to seizures, view in well lit conditions. ~00:30 - CRT video monitors in a darkened room not in sync with camera filming. Some strobing effects. 00:50 - Lights flickering higher than 3 hz with strong contrast changes. 00:52 - Fireworks. 00:54 - Extended flashlight strobing effects. 01:04 - Flickering lights/reflections with strong contrast. starting at 01:09:30 - Significant strobing/flashing with strong contrast changes. (Will update with end time mark post-seizure.)

There are many and they are intense. There was even a health warning at the beginning of the film concerning this, which I've never seen before. The villain uses strobe-like visuals in their attack.

When Dean has flashbacks they are shown as flashes of light.

Yes, in the episode “Gem Drill”

Season One - Episode 1 or 2, there's an entire scene that's based around strobe lighting

Several in the last chapter. For someone who isn’t sensitive to strobe effects, it gave me a headache

The last fight of a Neutral run and Pacifist run can have strobe effects.

A brief scene with flashing and strobe lights while on a slide in the funhouse.

Yeah, pretty much every episode.

There's a part where they have a flashback light that makes their memories back. That's where the effect happens.

The title sequence for seasons 1 and 3 contains several seconds of harsh camera flashes. S3E10: BoJack throws a party that has strobelights (4:00-7:30). S4E10: Light strobe effect (intermittently 0:00-1:40). S5E12: Several seconds of dim but rapid strobe right after the title sequence. S6E13: Dim but fast strobe effect for several seconds (24:30).

season two episode four at around 15 minutes in: character gets a flashback to having a seizure with lots of flashing lights

at the 50 minute mark, intense white/red flashing. avert yo eyes!!!

There are bright flashing lights during concerts. After a concert, Paul stands next to a pinball machine, the lights of which immediately flicker brightly.

In Harry Potter and the Philosopher's Stone (2001), there are bright flashes of light from lightning, and from spells.

Lightning creates a flashing effect.

There’s a flashing light at the Vortex Club party. It doesn’t stop while you’re there.