Is it haram to make reaction videos?

No, making reaction videos isn't haram in itself. Reacting to a clip, a recipe, a trailer, or a debate is a normal kind of content. It becomes a problem when the original content is haram to watch, when you mock people, or when you reuse someone's work in a way that breaks copyright and platform rules.

The basic rule

In Islam, everyday activities are allowed unless something specific makes them wrong. A reaction video is commentary, which is similar to reviewing a book or discussing the news. Many Muslim creators use reactions for good: responding to misinformation about Islam, reviewing halal food spots, or reacting to converts' stories. See Can I start a YouTube channel as a Muslim?

What you're reacting to matters

Your eyes and ears are a trust, and you'll be asked about what you used them for:

وَلَا تَقْفُ مَا لَيْسَ لَكَ بِهِۦ عِلْمٌ ۚ إِنَّ ٱلسَّمْعَ وَٱلْبَصَرَ وَٱلْفُؤَادَ كُلُّ أُو۟لَـٰٓئِكَ كَانَ عَنْهُ مَسْـُٔولًا "And do not pursue that of which you have no knowledge. Indeed, the hearing, the sight and the heart - about all those [one] will be questioned." Quran 17:36

Reacting to content with nudity, explicit scenes, or crude material means watching it and spreading it to your viewers. That multiplies the problem rather than excusing it.

Don't build content on mocking people

A lot of reaction content is about laughing at someone: their accent, looks, or a bad moment that went viral. The Prophet ﷺ said it is enough evil for a person to look down on his Muslim brother (Sahih Muslim 2564), and the Quran forbids ridiculing others. Fair criticism of ideas is fine; humiliating people for views is not.

Respect other people's work

Copyright: reusing long chunks of someone else's video without adding real commentary can break copyright law and platform rules, which Muslims are expected to honour. See Is it haram to download pirated movies or software?
Credit: name and link the original creator.
Honesty: don't fake reactions or use misleading thumbnails to bait clicks.

Earning money from reactions

If your reactions are clean, fair, and lawful, the income from them is generally fine. Scholars discuss the ads that appear on your videos, which you can partly control in your settings. See Can I make money from YouTube ads as a Muslim?

Key points

Reaction videos are allowed in principle.
Avoid reacting to haram content, since you'd be spreading it.
Don't mock or humiliate people for views.
Follow copyright rules and credit original creators.

Tip: Before filming, ask: "Will my viewers come away better informed or just entertained by someone's embarrassment?" Aim for the first and your channel will age well.