F5Bot is free, sends emails within 5-15 minutes of a Reddit post or comment matching your keyword, and supports up to 4 keywords on the free plan. Sign up at f5bot.com, confirm your email, and you are done in under 4 minutes.
Email is the only zero-cost channel for Reddit alerts that still works in 2026. Founders, researchers, and academics who need to track a niche topic without paying for a SaaS subscription get a complete answer here. The tradeoff is latency and weak filtering, but for low-volume keywords it is genuinely fine.
Go to f5bot.com and click Sign Up. Give a working email and a password. F5Bot sends a confirmation link.
Click the confirmation link in your inbox. F5Bot drops you into a dashboard with a single textarea labeled Words.
Add up to 4 keywords or phrases, one per line. Multi-word phrases like project management software work better than single words like saas which will flood your inbox.
Set an email filter or label in Gmail or Outlook. A filter on from:no-reply@f5bot.com with the action Apply label Reddit Alerts and Skip Inbox keeps your main inbox clean while still letting you batch-review.
Optional: forward F5Bot emails to a shared Google Group or distribution list so the whole team sees them without giving everyone the F5Bot login.
Wait 5-15 minutes for the first match. F5Bot polls Reddit on a rolling cycle and sends a single email per keyword hit with the post or comment URL, snippet, subreddit, and author.
Real payload shape for Email. Paste this into your handler to test the integration without waiting for a live match.
Subject: F5Bot found a match for 'wegovy side effects'
From: no-reply@f5bot.com
To: you@yourdomain.com
A Reddit comment in r/loseit matches your search term 'wegovy side effects':
Author: u/throwawayfit2024
Posted: 7 minutes ago
Subreddit: r/loseit
Post: Week 6 update on wegovy
Comment: 'The fatigue and dry mouth from wegovy side effects in week 3 nearly made me quit but it leveled out by week 5...'
URL: https://www.reddit.com/r/loseit/comments/abc123/_/xyz789
Unsubscribe or manage keywords: https://f5bot.com/manageA solo academic researcher tracked the phrase wegovy side effects across r/Semaglutide, r/loseit, and r/Mounjaro for a year, gathering 400+ first-person accounts for a peer-reviewed paper. Zero dollars spent.
A bootstrapped course creator monitored their course name plus the word refund across all of Reddit and was able to reply to dissatisfied buyers within hours, recovering 6 of 9 refund threads into resolved tickets.
A two-person ecommerce brand tracked their product category plus the word recommend, manually replied to 3-5 posts a week from their personal account, and attributed roughly 18% of their organic traffic to Reddit by month four.
MediaFast's Opportunity Finder scores Reddit threads by intent and pipes the high-signal ones to your channel of choice. No multi-tool setup.
free, 4 keywords, email only, 5-15 min latency, no subreddit filters. The default choice.
reddit.com: also free, less reliable since it depends on Google indexing Reddit, often misses comments entirely.
email plus Slack and webhook, subreddit filters, exclusion lists. Starts $19/mo.
email digests bundled with broader social monitoring. $99/mo and up.
free tool, results delivered via email digest if you opt in. Free.
Bootstrapped founders, academics, and solo operators who want zero-cost Reddit monitoring for under 5 keywords.
Free via F5Bot for up to 4 keywords. Paid email alert tools start at $19/mo and unlock subreddit filters and exclusion terms.
Pick a different channel or alert type and read the matched guide.
If you would rather skip the tool stack and just get the high-intent Reddit threads delivered, MediaFast ships an Opportunity Finder that scores threads by buying intent and pushes them to email or webhook. It sits in the same category as the tools listed above and stays competitive on price.
The questions teams actually ask before wiring this up.
Four. If you need more, your options are running multiple F5Bot accounts on different emails (against the terms of service), upgrading to a paid tool like Syften ($19/mo) or Notikey ($24/mo), or rolling your own with a Reddit API script if you can code.
Yes. The site has been running since 2015 and the operator posts uptime updates on r/F5Bot. It is a one-developer side project so support is asynchronous, but the core service is reliable.
Google's Reddit index is incomplete and biased toward posts that already have inbound links or high engagement. Comments are mostly invisible to it. F5Bot uses Reddit's own search and listing endpoints, so it catches both posts and comments and does not depend on Google's crawl.
Not on F5Bot's free plan. Workarounds: (1) refine to multi-word phrases that only appear in your target context, (2) set a Gmail filter to skip emails containing the noisy subreddit name, or (3) upgrade to Syften or Notikey for proper subreddit allow and block lists.
MediaFast's Opportunity Finder pulls Reddit posts where your product solves a stated problem and scores them by buying intent. One tool, no glue code.
Try Opportunity Finder