Reddit Keyword Alerts

F5Bot is a free service that watches Reddit, Hacker News, and other sites for the keywords you pick and emails you when one comes up. Give it a word or phrase, and you get an email when that word shows up in a new Reddit post or comment. Most people find F5Bot while looking to watch their company name, but the same setup works for anything you can put into words.

What people watch for

People point it at all kinds of things:

Your own brand, product, or username.
A competitor's name, to see what people say about them.
A product category you sell into, like "standing desk" or "password manager."
A phrase that means someone needs what you do, like "looking for a developer."
A hobby or niche term you just want to follow.
Your open-source project, so you hear when someone brings it up.

If you can describe it as a word or short phrase, you can watch for it.

How matching works

F5Bot looks at the title of a post, the link it points to, and the text of every comment. When your keyword appears in any of those, you get an email. It does not look at usernames unless you ask it to.

Matching is not case-sensitive, so "Python" and "python" are the same to it. By default it matches the letters wherever they appear, which means a keyword like "cat" would also match "category" and "education." If that is a problem, turn on whole-word matching and it will only match "cat" on its own. The full set of rules is on the keyword documentation page.

Keeping the noise down

The first time you watch a common word, you will probably get matches you do not care about, and a handful of settings trim it down:

Whole-word matching keeps "cat" from matching "category."
Site filters let you stick to one place. Use only-reddit to ignore Hacker News and Lobsters, for example.
Subreddit filters with only-url=/r/somesubreddit/ keep you inside the communities you care about.

One common mix-up: people combine only-reddit with only-url= expecting it to mean "this subreddit only," and instead get all of Reddit. There is a short write-up on why that happens here.

For real control, F5Bot's paid plans add include and exclude filters, which let you require or forbid other words near your keyword. The top tiers go a step further with F5Bot's AI-powered filtering, which judges a match by what it means instead of the exact letters, which is what finally makes a noisy keyword usable.

When the alerts arrive

F5Bot groups your matches together so you get a tidy email instead of a pile of them. How fast they go out depends on your plan. The free plan sends on a delay. Paid plans send promptly, and can also hold alerts for a daily digest at times you pick. You can see the differences on the pricing page.

Free and paid

F5Bot's free plan covers a lot of people and runs fine for years. Its limits are the delay before alerts go out, no monitoring of the most common keywords, and a cap on how many matches a single keyword sends in a day. Paid plans deliver promptly, raise the caps, open up common keywords, and add the include, exclude, and AI-powered filters. If you are doing this for work, they are worth comparing on the pricing page.

Get started

Make a free account, add one keyword, and wait for the first email. You can always add more later. If you are setting this up to watch your own company, the brand mention guide goes deeper on that.