How to Monitor Comments on a Reddit Post and Find New Replies

Reddit can notify you about some activity, but that is not the same as keeping a complete record of a discussion. Reddit’s help center says notifications for your own post cover comments made directly to the post; replies to someone else’s comment do not trigger the same notification. Users following other people’s posts also report that they do not receive every new comment. If one thread matters—a product launch, AMA, complaint, incident, campaign, or feature-request discussion—the dependable

Use a post URL when the conversation matters more than discovery

Keyword monitoring asks, “Which new discussions mention this topic?” Post-level comment monitoring asks, “What has changed inside this one discussion?”

Start from a known Reddit post URL when:

• you launched a product and want to follow reactions;
• an AMA continues receiving questions;
• a complaint or support issue is attracting replies;
• customers are comparing your product with a competitor;
• a research thread contains useful answers over several days;
• an old post becomes active again after being linked elsewhere.

This workflow should not search Reddit for more posts. Its only discovery target is the comment tree under the supplied URL.

Why Reddit notifications are not enough for complete thread monitoring

Reddit notifications are useful for personal participation. They are not designed as a complete export of every visible branch in a discussion.

Reddit’s official help page explains that a user who enables comment notifications for their own post receives alerts for direct comments, also called parent comments, but not when someone replies to another commenter. Recent r/help discussions describe similar gaps when users follow posts they did not create.

A monitoring dataset solves a different problem:

Define the comment identity before the first run

Use Reddit’s comment_id as the primary key. A comment permalink is a useful secondary identifier and makes every alert reviewable.

Keep these fields:

• comment_id;
• parent_comment_id;
• depth;
• author;
• comment_text;
• score;
• published_time;
• permalink;
• is_deleted;
• collected_at.

Also repeat the post title, canonical post URL, subreddit, and current post comment count on the result rows or in a separate post table.

The parent ID and depth are important. Without them, a reply such as “that worked” becomes detached from the advice it confirms. With them, you can reconstruct the branch and understand the conversation.

Build a Reddit post comment monitor in BrowserAct

BrowserAct’s Reddit Post Comments Scraper starts from one public post URL. The current template supports comment sorting, nested replies, deleted-comment markers, comment IDs, parent IDs, reply depth, permalinks, and a configurable limit of up to 500 comments.

The template page estimates 33–49 credits for its default workflow. Start with 20 comments while validating the output, then increase the limit only if the thread warrants it.

1. Open BrowserAct Dashboard

Click the left-side + to create a Bot, start from a Reddit quick-start option, or paste the prompt directly into the center Agent input. If you already know the post URL, you can also open the template and use Run task.

Current BrowserAct Agent Built interface from the Reddit Post Comments Scraper documentation, captured from the template published in September 2026.

2. Copy the complete prompt

Replace the sample URL with the exact public Reddit post you want to follow. Use new as the comment sort for a recurring monitor.

Create a reusable Bot that monitors visible public comments and nested replies on one Reddit post.
 
Reusable inputs:
- post_url: the exact public Reddit post detail URL
- comment_sort: new
- include_replies: true
- comment_limit: 50
 
For each run:
1. Validate and normalize the supplied Reddit post URL.
2. Open the public post and load the visible comment thread sorted by New.
3. Include top-level comments and nested replies.
4. Return up to the requested comment limit.
5. Preserve the reply hierarchy and mark deleted or removed comments without inventing an author or missing text.
 
Return these post fields:
- post_title
- post_url
- subreddit
- post_author
- post_score
- post_comment_count
 
Return one row per visible comment with:
- comment_id
- parent_comment_id
- depth
- author
- comment_text
- score
- published_time
- permalink
- is_deleted
- collected_at
 
Deduplicate the current run by comment_id. If I provide a previous export, compare comment_id values and label every row as new, updated, or previously_seen. Return new rows first. Preserve a known comment when its score or deleted status changes.
 
Use public or authorized pages only. Do not vote, comment, follow, message users, join communities, or change any account. If Reddit requests login, CAPTCHA, 2FA, age confirmation, membership approval, or restricted access, pause and ask me to complete it manually.
 
Return a CSV-ready table and JSON. Keep the canonical post URL and comment permalink on every record.

Cross-run storage matters: the template removes duplicate IDs within a run. To identify comments that are new since yesterday, retain the previous comment_id list in a sheet, database, or automation step and compare the next export against it.

Scrape data from any website. Describe the data you need. Get a Bot—a reliable, reusable scraper. Try: “Monitor this public Reddit post and return only comment IDs I have not seen before.” Get your Bot — Free

3. Handle login only when asked

The template is built for public Reddit post pages and normally does not require a login. If an access check appears, allow BrowserAct to pause. Complete an authorized login, CAPTCHA, 2FA, or age confirmation yourself before resuming.

Do not treat a comment count as proof that every comment is visible. Reddit may show a higher count than the number of accessible rows when comments are removed, deleted, filtered, collapsed, or unavailable.

4. Review, dedupe, and export

Run the Bot once with comment_limit: 20. Verify five things before scheduling it:

1. Every row belongs to the supplied post URL.
2. Top-level comments have depth: 0 and no parent comment ID.
3. Replies retain the expected parent ID and greater depth.
4. Deleted or removed content is marked instead of silently replaced.
5. Permalinks open the intended comment when the comment remains public.

Export the result as CSV or JSON. Save the first run as the baseline. On later runs, compare comment_id against the baseline and send only new IDs into the alert queue.

The current BrowserAct result interface was validated on August 26, 2026. The example monitors an older public r/ChatGPT post, which is useful for verifying hierarchy and deleted-comment handling but is not presented as fresh market data.

How to return only new comments on later runs

Use a master table with one row per comment. Make comment_id unique.

For each new run:

1. Load the existing set of comment IDs for the post.
2. Run the scraper against the same canonical post URL.
3. Match rows by comment_id.
4. Insert IDs that have never appeared.
5. Update known IDs only when tracked fields changed.
6. Set last_seen_at for comments still visible.

Classify the result:

Preserve the reply tree instead of sorting comments into a flat list

For monitoring, new is the useful collection sort because recent comments appear first. For analysis, the thread hierarchy still matters more than the display order.

Reconstruct a branch by joining parent_comment_id to comment_id. A top-level comment has no parent comment ID and starts a branch. Its replies point back to it, and deeper replies point to the comment immediately above them.

This lets you answer questions that a flat comment export cannot:

• Which recommendation received agreement or pushback?
• Did the original poster respond to a complaint?
• Which objection generated the longest reply chain?
• Did a solution actually resolve the reported problem?
• Are several replies repeating one issue or discussing different issues?

When sending an alert about a nested reply, include the comment text, its permalink, the parent comment text, and the post title. A one-line reply without those references often cannot be interpreted correctly.

Choose the monitoring frequency from the response window

Do not run every thread at the same frequency.

For an alert workflow, send only the new rows to Slack, email, Telegram, or another internal destination. BrowserAct documents API JSON, n8n, Make, Zapier, MCP, and spreadsheet export as downstream options. Keep the source permalink in every alert so a reviewer can inspect the live context.

Avoid these monitoring mistakes

Comparing comment text instead of IDs

The same sentence can appear more than once, and edited text can change. Use comment_id first and text only as content.

Treating post comment count as the number of extractable rows

The count may include comments that are removed, deleted, filtered, collapsed, or outside your configured limit. Report collected rows and displayed count separately.

Dropping deleted comments

A deleted marker is still part of the thread structure. Keep the ID, parent link, depth, permalink, and deleted status while leaving unavailable author or text fields empty.

Alerting on every score change

Scores can change often and usually do not require immediate review. Reserve alerts for new comments, deletion-status changes, or business rules tied to the thread.

Monitoring forever

Every watched post needs an owner and a stop condition. Archive a monitor after the event ends, the issue is resolved, or the thread remains inactive for the agreed period.

Final checklist

• Start from the canonical public Reddit post URL.
• Sort comments by New for recurring monitoring.
• Include replies when child discussions matter.
• Store comment ID, parent ID, depth, permalink, and deleted status.
• Run a small baseline before increasing the limit.
• Compare comment IDs across runs.
• Alert on new rows, not the entire thread.
• Include parent context in alerts for nested replies.
• Distinguish disappeared comments from confirmed deletions.
• Set an owner, cadence, and stop condition for every monitored thread.

With those rules in place, one Reddit post becomes a controlled monitoring source instead of a page someone must remember to refresh.