What is rule-based comment moderation?

A rule is one sentence you write once: when a comment arrives, if it matches, then do this. You decide, not an AI, so every decision is predictable, auditable and traceable to the rule that made it.

On this page11 sections
  1. 1The short version
  2. 2When, If, Then
  3. 3First match wins
  4. 4Test it, then watch it
  5. 5Why rules, not AI alone
  6. 6Rules vs AI-only
  7. 7When to use which
  8. 8When a rule is the wrong tool
  9. 9How Social Tools does it
  10. 10Try it on a sample comment
  11. Related guides

The short version

Rule-based moderation means you decide, in plain words, what happens to a comment. The software follows those words exactly, every time, and logs what it did.

Automated moderation splits into two camps. With AI-only moderation, a model decides what to hide or allow from patterns it learned, and you set the sensitivity. With rule-based moderation, you write the conditions and the actions, and the engine carries them out. The answer to “why was this hidden?” is the rule itself: you can read it, change it and test it before it touches a real comment.

When a comment arrives on your Instagram and Facebook posts, if it contains “how much”, “price” or “ship”, then reply with the answer and the product link. A real rule, written the way you write it in Social Tools.

When, If, Then: how a rule engine works

Every rule has the same three parts. When is the trigger, If is the conditions, and Then is the actions. Here is one comment going through them, line by line.

One comment on a Cat Novaa Instagram post, start to finish.

PartOn this commentTime
WhenA comment arrives on a post, or a DM comes in @dani.r · Instagram postHow much is the linen shirt? Ship to Canada? 9:02 am
IfWords, sentiment, intent, platform, author. All must be true. Matched two of the rule’s words
how muchshipRule: Answer price and link questions
9:02 am
ThenReply, private reply, DM, hide, delete, like, send it to you, or a reply drafted by AI Yes, we ship to Canada. Price and sizes are in your DMs: cmtly.com/linen-shirt 9:02 am
Result 1 click1 click on cmtly.com/linen-shirt, the reply’s own link 9:06 am

The last line is what makes a rule worth writing. Each reply can carry its own tracked link, so you see what the answer led to: a click. And every line is logged: the comment, the rule and branch that acted, what it did, when, and who wrote the rule. How we count a result.

First match wins

Rules are checked in priority order, top to bottom. The first one whose conditions all match acts, and the rules below it don’t run for that comment. Inside a rule, its branches are checked the same way. So put narrow rules above broad ones: spam first, then specific questions, then catch-alls.

Cat Novaa’s four rules, and the comment above.

#Rule@dani.r’s comment
1Hide spam and abuseLiveNo match
2Answer price and link questionsLiveMatch: replied
3Send unhappy customers to youLiveNot checked
4DM the link on “LINK”Watch modeNot checked
One rule acted. The rest stayed quiet.1 reply

A rule in watch mode still counts as the match. If it’s first in line, it records what it would have done, and the live rules below it stay quiet too. That keeps a test from colliding with the rules you already trust.

Test it, then watch it

The biggest advantage of rules: you can test any rule on a sample comment before it goes live. Type a comment in, or pick a built-in example, and see exactly which branch would act and why, condition by condition. Tune it until it’s right. No AI-only tool can do this, because its decisions can’t be predicted or replayed. Start your free trial to try the rule builder.

Then let it watch. Any rule can run in watch mode, and starters begin there: it runs on your real comments and records what it would have sent, without sending anything. When the log reads right, switch it to Live.

The watch log for DM the link on “LINK”, this week.

CommentWould haveWhen
@lea.mLINKSent a DM with cmtly.com/linen-shirtMon 9:12
@sam.kthis colour is unrealNothing: no matchMon 9:40
23 would send this weekSent for real0

Why rules beat AI alone, for teams that need control

  • You know exactly why a decision was made

    When an AI hides a comment, the best you get is “negative sentiment detected.” With a rule you see: matched the words giveaway and DM me, so branch 2 of “Spam detection” hid it, under a rule Sarah wrote on 15 June. That’s the difference between guessing and knowing.

  • No false positives from generic AI

    AI models are trained on general data. They don’t know that “cancer” is a research term for a medical nonprofit, or that “kill it” means “great job” in your community. With rules, you control the vocabulary: your rules, your context, your decisions.

  • Test before you trust

    Try a rule on a sample comment, then let it watch your real ones in watch mode. Nothing goes live until you say so.

  • Prove it to clients and regulators

    When a client asks “why was this comment hidden?”, or a regulator asks how you moderate, a rule is the answer. An AI-only tool gives you a confidence score. For agencies managing brand safety and for regulated industries, that difference matters.

  • AI still helps. It just doesn’t decide.

    Rule-based doesn’t mean no AI. Sentiment and intent are AI-scored conditions you can use in a rule. You write “if sentiment is negative and the comment contains a link, then hide it”. The AI scores the sentiment; the rule makes the call.

Rule-based vs AI-only, line by line

AI-only catches new patterns with less setup. Rules give you control and a record. An AI-only tool also runs the same model for everyone, so your comments get the same treatment as anyone else’s.

LineRule-basedAI-only
Decision transparency Yes: Traceable to the rule that acted No: “Negative sentiment detected”
Customization Yes: Brand-specific rules Partly: A sensitivity slider
Testing before it goes live Yes: Try it on a sample comment, then watch mode No: Deploy and hope
Audit trail Yes: Per decision, per rule Partly: Aggregate analytics only
Catches new kinds of attack Partly: Needs a rule update Yes: Pattern recognition
Setup time Partly: Define your rules first Yes: Turn it on and it works
More than one platform Yes: Same rules on every platform Partly: Varies with each platform’s AI
Client reporting Yes: Shows what was moderated and why No: Shows volume, not reasoning

When should you use rule-based moderation?

Rules are best when

  • You need to prove moderation decisions to clients or regulators
  • Your brand has its own terms that generic AI gets wrong
  • You moderate on more than one platform and want the same rules on each
  • You’re an agency with several clients, each with its own policy
  • You want to test before it goes live
  • You need an audit trail for compliance, clients or internal review

AI-only may be enough when

  • You moderate a single brand with generic needs
  • You don’t need to explain decisions, only cut the volume
  • Speed of setup matters more than precise control
  • You’re a solo creator with one account and no compliance requirements

When a rule is the wrong tool

Some comments need a person. “Ordered 2 weeks ago and nothing yet, order #4471” is not a question a template should answer. Write a rule that sends it to you, as the starter Send unhappy customers to you does: it lands in Needs you with nothing sent. You answer it yourself, and the rules keep that queue short.

A good setup answers the routine questions, hides the spam and hands you the rest. At Cat Novaa, that left 9 of 547 comments for a person this week.

How Social Tools implements rule-based moderation

Social Tools is built from the ground up as a rule engine: you write the rules, the engine carries them out, and AI helps where it’s useful.

Rule builder
Rules with several branches. Each branch joins its conditions (words, sentiment, intent, platform, author) with AND, and can run several actions: reply, private reply, DM, hide, delete, like, send it to you, or an AI-drafted reply.
Try it on a comment
Test a rule on a sample comment before it goes live: pick a built-in example or type your own, and see which branch would act and why, condition by condition.
Priority order
Higher rules are checked first, and a rule’s branches top to bottom. First match wins: predictable, debuggable, auditable.
Per-decision log
Every action is recorded: which comment, which rule, which branch, who set it up, and when. From comment to decision, for your own review or a client’s.
One set of rules, every platform
Write a rule once and it runs on Instagram and Facebook today; TikTok, YouTube, X (Twitter), Reddit and Discord are coming. Platform conditions tune a rule for one of them when you need to.
AI-assisted, not AI-decided
Sentiment and intent are available as conditions, and AI can draft a reply. AI gives the signal; your rule makes the decision.

Every rule can be tested before it runs. Start your free trial to try the rule builder yourself. No credit card required.

Try it on a sample comment

Pick a comment and see what the starter rules do with it, line by line, before you connect anything.

Pick a sample comment

What happened to @dani.r’s comment

PartOn this comment
When@dani.r · Instagram postHow much is the linen shirt? Ship to Canada?
If Matched the starter’s words how muchship Rule: Answer price and link questions
ThenYes, we ship to Canada. Price and sizes are in your DMs: cmtly.com/linen-shirt
Result 1 click On the reply’s own link

What happened to @_bot_crypto’s comment

PartOn this comment
When@_bot_crypto · Instagram postDM me to earn $5k/week
If Matched the starter’s words DM meearn Rule: Hide spam and abuse
ThenHidden. No reply sent.
Result Hidden 1 second after it landed. Hiding is free: no automation used.

What happened to Priya S.’s comment

PartOn this comment
WhenPriya S. · Facebook postOrdered 2 weeks ago and nothing yet, order #4471
If Matched the starter’s condition sentiment: negative Rule: Send unhappy customers to you
ThenSent to Needs you, in your inbox. No reply sent.
Result Needs you For Maya. Waiting 4 min.
Start free trial Book a demo Free for 10 days at Pro, 700 automations, no card. Starters begin in watch mode on your own comments.
Try it on a sample comment