Reddit Keyword Alerts: F5Bot, Its Alternatives and a Setup That Finds Buyers

Reddit is where people ask strangers for honest recommendations. If someone writes "what do you use for invoicing as a freelancer?" and you sell invoicing software, you want to know within the hour, not next week.

Keyword alerts make that possible. This guide covers the tools, how to set them up, and the part most people skip: choosing keywords that surface buyers instead of noise.

The quick answer

• F5Bot is the free standard. It emails you when your keywords appear on Reddit, Hacker News or Lobsters.
• Paid tools (Prospy, Syften, Octolens and others) add more platforms, Slack and webhook delivery, and AI filtering that ranks posts by intent.
• The keywords matter more than the tool. Brand name alone finds fans. Problem phrases and competitor names find buyers.
• Test a keyword before you set an alert. The free Social Mention Search shows the last 7 days of mentions on Reddit and ten other sources, scored for intent, so you can see whether a phrase finds buyers or noise.

Option 1: F5Bot

F5Bot has been around for years and does one thing well. You sign up, add keywords, and it checks Reddit posts and comments, Hacker News and Lobsters every few minutes.

Plans as of November 2026:

Plan	Price	Keywords	What you add
Free	$0	Limited	Email alerts, basic filter flags
Silver	$12.99/mo	20	Advanced filters, full post text, no ads
Gold	$49.99/mo	200	RSS and JSON feeds, AI filtering, Slack and Discord

Delivery can be instant, batched or a daily digest. F5Bot also has flags to limit a keyword to a single site, for example Hacker News only.

Where it falls short:

• Three sites only. No X, LinkedIn, Bluesky or YouTube, where many of the same conversations happen.
• Keyword matching, not meaning. A post that mentions "notion" because someone had a notion of quitting will reach your inbox.
• No ranking. Every match looks equally important in your email.

For a solo founder tracking a brand name, the free plan is often enough. Once you track generic problem phrases, the volume becomes unmanageable without filtering.

Option 2: Google Alerts with site:reddit.com

You can create a Google Alert for "your keyword" site:reddit.com. It is free and takes a minute. It is also slow and incomplete: Google has to index the thread first, comments are mostly missed, and alerts often arrive days late. Fine as a backup, not as your main source.

Option 3: Multi-platform tools with AI scoring

When you need more than Reddit, or need to know which mentions matter, a paid tool earns its cost.

• Prospy watches 12 platforms, including Reddit, X, Hacker News, LinkedIn, Bluesky and YouTube, and scores every mention for relevance and buying intent. Alerts go to email, Slack, Discord or a webhook, and you can set a minimum score so you only hear about the good ones. It scans once a day and sends one ranked batch, so it suits a daily routine rather than minute-by-minute pings. See pricing.
• Syften covers Reddit, Hacker News, GitHub, Indie Hackers, Stack Exchange and many developer communities, with X as an add-on. From $29.95/month.
• Octolens is built for dev-tool companies with brand and developer monitoring across Reddit, X, LinkedIn, GitHub and more. From $159/month billed annually.

See our comparison of Syften and Prospy if you are choosing between those two.

Choosing keywords that find buyers

Most alert setups fail because of the keywords, not the tool. Use four groups.

1. Your brand

Your product name, common misspellings and your domain. These find people already talking about you: questions, praise, complaints. Answer every one.

2. Competitors

Competitor names, ideally paired with words that signal switching:

• "[competitor] alternative"
• "[competitor] too expensive"
• "switching from [competitor]"
• "[competitor] vs"

Someone unhappy with a competitor is the warmest lead you will find on Reddit.

3. Problem phrases

The words people use before they know your category exists. If you sell a social listening tool, people rarely write "I need social listening". They write "how do I track mentions of my startup" or "tired of searching Reddit by hand".

Find these phrases by reading 20 to 30 threads in your niche and copying the exact wording.

4. Request phrases

Generic phrases that signal someone is shopping, combined with your category:

• "any recommendations for [category]"
• "what do you use for [job]"
• "looking for a tool that [job]"
• "is there an app that [job]"

Cutting the noise

Whatever tool you use:

• Use exact phrases in quotes for anything with more than one word.
• Exclude obvious false positives. Job posts, hiring threads and memes are the usual offenders.
• Limit generic terms to relevant subreddits when your tool allows it.
• Review weekly. Delete keywords that produced nothing useful in two weeks. Add phrases you saw in good threads.
• Mark irrelevant results when your tool learns from feedback. In Prospy, marking a mention irrelevant removes it and blocks that post from coming back.

What to do when an alert fires

Speed matters. Reddit threads get most of their replies in the first few hours, and an answer posted early sits near the top.

1. Read the whole thread and the subreddit rules before replying.
2. Answer the question first. Give a real recommendation, even if it is not you.
3. Mention your product only when it fits, and say that you built it.
4. Never paste the same reply twice. Moderators and users notice, and so do Reddit's spam filters.

For a full playbook on turning these threads into customers, read our guide to Reddit lead generation.

FAQ

Is F5Bot free?

Yes, F5Bot has a free plan with email alerts for Reddit, Hacker News and Lobsters. Paid plans start at $12.99 a month for 20 keywords and advanced filters.

Does Reddit have built-in keyword alerts?

Reddit has no built-in keyword alerts for regular users. Reddit Pro offers a free Trends tool for businesses that shows keyword conversation volume, but it is a research tool, not an alert system.

What is the best F5Bot alternative?

It depends on what you are missing. For more platforms and intent scoring, Prospy covers 12 sources (pricing). For developer communities, Syften. For larger dev-tool teams, Octolens.

How fast are Reddit keyword alerts?

F5Bot checks every few minutes. Google Alerts can take days. Paid tools range from near real-time to hourly, depending on the tool and plan. Prospy scans once a day and sends one batch ranked by intent, trading speed for less noise.

Get Reddit alerts that rank buyers firstProspy scores every mention across 12 platforms for intent.