Most people who want to start a reaction channel never publish anything. Not because they lack a camera or a personality, but because the setup phase is a trap. You research gear. You watch tutorials about editing software you have not bought yet. You worry about copyright. Three weeks pass and the folder on your desktop is still empty.
This guide is written to get you past that. It is the order of operations that actually works: pick a niche, publish before you optimize, and let the first ten videos teach you what no tutorial can.
Step 1: Pick a niche with an endless supply
The single biggest predictor of whether a reaction channel survives its first six months is not talent. It is supply. Can you sit down every week and find something new to react to without agonizing over it?
Run every candidate niche through three questions:
Does new material arrive on a schedule? Music reactions have this. So do trailer reactions, episode reactions, and sports. First-time watches of a beloved back catalogue do not: you burn through the good stuff in two months and then you are reacting to films nobody searches for.
Is there existing search demand? When a trailer drops, tens of thousands of people search for reactions to it within hours. That demand exists before your video does, which is the opposite of most content, where you have to manufacture interest from nothing.
Can you say something? Pick the thing you already text your friends about at midnight. If you have no opinions about a category, the camera will make that obvious in about eleven seconds.
Trailer reactions score well on all three, which is why they are the recommendation here for beginners. Two to three minutes of runtime, a fresh batch every week, and a built-in audience that is already looking.
Step 2: Choose your format before you buy anything
There are three reaction formats worth knowing, and you should commit to one for your first ten videos.
The vertical clip. Source content on top, your face below, sixty to ninety seconds, built for TikTok, Reels, and Shorts. This is the fastest format to make and the fastest to grow with, because short-form platforms will show your video to strangers without requiring you to have an audience first.
The long-form watch-along. Ten to thirty minutes, picture in picture, aimed at YouTube watch time and eventually ad revenue. Higher ceiling, much slower start, and far more editing per upload.
The commentary cut. You react, then you cut it down to only the moments where you had something to say. Best retention of the three, most work.
Start vertical. You can graduate to long-form once you know what your audience responds to, and the clips you make in month one still serve as promotion for the longer videos in month six.
Step 3: Buy almost nothing
Here is the entire list of what actually changes how your reactions look and sound, in priority order.
Light on your face. Sit facing a window during the day, or put any cheap lamp behind your camera pointed at you. This is the difference between looking like a creator and looking like a hostage video, and it costs nothing.
Audio that is not echoey. Record in a room with soft things in it: a bed, a couch, curtains. Wired earbuds with a mic beat your laptop microphone. A dedicated mic is a month-three purchase, not a day-one one.
A stable camera at eye level. Your phone on a stack of books is fine. Below eye level is unflattering, above is fine, wobbling is unwatchable.
That is it. No green screen, no ring light, no capture card, no camera. Every dollar you spend before your tenth video is a dollar spent avoiding the actual work.
Step 4: Record your first one today
This is where most guides tell you to download editing software. Skip it. The friction of a full editing workflow is what kills beginner channels, and for trailer reactions specifically you do not need one.
On Reactr, every upcoming film has a page with the trailer and a recorder built into the browser. You pick a film, hit record, the trailer plays while your camera rolls, you pause whenever you have a take, and you get a finished vertical clip with your handle on it. No install, no timeline, no export settings.
Pick something in the next few weeks with real search interest behind it. As of this week, good starting points include Colony, which is the highest-interest new title on the slate right now, the horror sequel Insidious: Out of the Further, and the long-delayed Coyote vs. Acme, which carries a whole news story with it that people want opinions on. If you would rather aim at the biggest possible search volume, the tentpoles are sitting right there: Avengers: Doomsday and Dune: Part Three. Browse the full slate at the reactions library and pick whatever you would actually watch.
Step 5: Your first ten videos, planned
Do not think of these as your channel. Think of them as tuition. Here is the split that teaches you the most in the least time.
Videos 1 to 3: whatever is biggest. React to the three highest-interest trailers you can find. You are learning the mechanics: framing, pacing, when to pause, how you sound. Publish them even though you will hate them.
Videos 4 to 6: whatever is yours. Now go narrow. Pick the genre you genuinely know best, horror or anime or indie sci-fi, and react to titles inside it. This is where a returning audience starts, because a stranger who agrees with your take on one horror trailer will come back for the next one.
Videos 7 to 9: repeat your best one. Look at which of the first six did best and make three more like it. Same genre, same length, same energy. Resist the urge to reinvent.
Video 10: the one with a hook. By now you know what you sound like. Make one with a real opinion in the title: a prediction, a ranking, a take you would defend. This is the video that gets shared.
Publish on a fixed cadence, twice a week beats daily-then-nothing, and put your handle on every clip so the person who finds you on TikTok can find you again anywhere.
Step 6: What to actually measure
Ignore subscribers for the first month. They are a lagging indicator and watching them will make you quit. Watch these instead:
Retention at three seconds. If people leave immediately, your opening frame is the problem, not your personality. Start mid-thought, never with an introduction.
Comments per view. A video with fifty views and six arguments in the comments is more valuable than one with two thousand views and silence. Arguments mean you said something.
Repeat viewers. The only number that compounds.
The part nobody tells you
Reaction channels are a game of accumulated attempts. The tenth video is better than the first for reasons you cannot skip past by planning harder, and the fiftieth is better than the tenth. Everything in this guide is designed to reduce the cost of one attempt so you can afford more of them.
One more thing worth doing early. When you record on Reactr under your own account, every clip is attributed to you from the beginning, and that history is what builds your Reactor profile. Attribution is live today, and payouts open as sponsored campaigns come online. The point of starting now is that your track record accumulates while it is still cheap to be early.
Stop reading. Pick a trailer, sit facing a window, and publish the ugly first one today.