Comparison
ReplyHey vs Syften
Syften is what F5Bot grows up into: fast alerts, many platforms, real filtering. It still ends where ReplyHey begins — at the moment you have to decide and write.
Syften details read from their site in August 2026. Pricing moves — check theirs before you decide.
What Syften is
Syften is an AI-filtered keyword monitoring tool: you define filters, and it surfaces brand mentions, competitor mentions, problem phrases and buying-intent conversations as they appear across an unusually long list of places — Reddit with at most a minute’s delay, X within fifteen, plus Hacker News, Indie Hackers, GitHub, Product Hunt, the Stack Exchange family, Slack communities, newsletters, YouTube, podcasts, Bluesky, Mastodon and the public web. The AI filtering suppresses spam, duplicates and weak matches, and results arrive by email, Slack, RSS, API or webhooks, with a searchable archive behind them.
Plans are metered by filters and results: Entry at $29.95/month for 3 community filters and 100 results a day, Standard at $49.95 for 20 and 200, PRO at $119.95 for 100 and 500, all with a 14-day no-card trial that includes the last 60 days of mentions. It does not draft replies and does not post — deliberately. It is an alert tool, and a disciplined one.
ReplyHey watches one platform and finishes the job on it: threads scored 0–100 against what you sell with the evidence quoted, the subreddit’s live rules checked, the reply drafted in your voice, and a posting calendar for the weeks when the alerts would have been quiet anyway.
Where Syften is better
- Speed: a minute’s delay on Reddit. ReplyHey sweeps daily; if being the first comment matters, Syften wins that race.
- Coverage nobody else on this page matches — including Slack communities, Indie Hackers and the public web.
- The AI filter genuinely reduces alert fatigue, which is the historic failure mode of this category.
- A 14-day trial with 60 days of history, so you can judge your niche’s volume before paying.
Side by side
| ReplyHey | Syften | |
|---|---|---|
| What it watches | Reddit, swept daily | Reddit in ~1 minute, plus 15+ other platforms |
| Setup | Paste your URL; keywords and subreddits derived | You define keyword filters |
| Deciding what matters | Scored 0–100 with the evidence quoted | AI filtering removes spam and weak matches; you judge the rest |
| The reply | Drafted in your voice; you edit and post | Not its job |
| Subreddit rules | Checked live; DM draft where promotion is banned | Not its job |
| Posting plan | A two-week calendar per subreddit | No |
| Metering | None | Filters and results per day, by plan |
| Trial | 3 days, no card | 14 days, no card, with 60 days of history |
| Price | $24.99/month, unlimited websites | $29.95 to $119.95/month |
Where we differ
Whichever you pick: nothing should post to Reddit as you. That is the line the account bans are on.
ReplyHey vs Syften: questions
Is Syften or F5Bot the better alert tool?+
Syften is faster on X, covers far more platforms, filters better and charges for it; F5Bot is free and covers Reddit, Hacker News and Lobsters. If you just want the alarm, start with F5Bot and upgrade to Syften when the volume hurts. If you want the decision and the reply handled too, that is what ReplyHey is for.
Why is ReplyHey daily when Syften is a minute?+
Because the threads that convert — “what should I use for X” — stay alive and rank in Google for months, so an hour rarely matters. Deliberate trade: ReplyHey spends its effort on scoring, rules and drafting rather than latency. If you need to be first on breaking threads, use a fast alarm; some people run both.
Does Syften draft replies now?+
Not as of when we read their site — it delivers alerts and integrations and leaves the writing to you, which fits its design. If that changes, their site is the authority, and the date we checked is at the top of this page.
More comparisons
See all →Try ReplyHey before you decide
Paste your URL, see the subreddits and the first leads, and compare it against Syften with your own niche rather than ours. No card, nothing to cancel.