How to Scrape Reddit Comments with Kotlin

Extract comments data from Reddit

📱 Using Kotlin

Overview

Learn how to scrape Reddit comments using Kotlin. This comprehensive guide will walk you through the entire process, from setup to implementation.

What You'll Learn

  • • Setting up your development environment
  • • Installing the required HTTP client
  • • Authenticating with the ScrapeCreators API
  • • Making requests to Reddit
  • • Handling responses and errors
  • • Best practices for production use

What You'll Get

  • • Access to comments data
  • • JSON formatted responses
  • • Real-time data access
  • • Scalable solution
  • • Error handling patterns
  • • Performance optimization tips

Prerequisites

1. API Key

First, you'll need a ScrapeCreators API key to authenticate your requests.

Sign up at app.scrapecreators.com to get your free API key with 100 requests.

2. Development Environment

Make sure you have the following installed:

  • • Kotlin and its dependencies
  • • A code editor (VS Code, Sublime, etc.)
  • • Basic understanding of API requests
  • • Command line interface access

Step 1: Install HTTP Client

OkHttp is an HTTP client for Kotlin/Java

gradle
implementation "com.squareup.okhttp3:okhttp:4.9.3"

Step 2: API Implementation

Now let's make a request to the Reddit API using Kotlin. Replace YOUR_API_KEY with your actual API key.

Kotlin
import java.net.http.HttpClient
import java.net.http.HttpRequest
import java.net.http.HttpResponse
import java.net.URI
import java.net.URLEncoder
import java.nio.charset.StandardCharsets

class Scraper {
    companion object {
        private const val API_KEY = "YOUR_API_KEY"
        private const val BASE_URL = "https://api.scrapecreators.com"
        private const val ENDPOINT_PATH = "/v1/reddit/post/comments"
        
        @JvmStatic
        fun main(args: Array<String>) {
            try {
                val result = scrape()
                println("Response: $result")
            } catch (e: Exception) {
                println("Error: ${e.message}")
            }
        }
        
        fun scrape(): String {
            val client = HttpClient.newHttpClient()
            
            // Build query parameters
            val params = mapOf(
                "url" to "https://www.reddit.com/r/AskReddit/comments/ablzuq/people_who_havent_pooped_in_2019_yet_why_are_you/",
                "cursor" to "ed1lvsa,ed3fnpq,ed25l2w",
                "trim" to "false"
            )
            
            val queryString = params.entries.joinToString("&") { (key, value) ->
                "${key}=${URLEncoder.encode(value, StandardCharsets.UTF_8)}"
            }
            
            val url = "${BASE_URL}${ENDPOINT_PATH}?${queryString}"
            
            val request = HttpRequest.newBuilder()
                .uri(URI.create(url))
                .header("x-api-key", API_KEY)
                .header("Accept", "application/json")
                .GET()
                .build()
            
            val response = client.send(request, HttpResponse.BodyHandlers.ofString())
            
            if (response.statusCode() == 200) {
                return response.body()
            } else {
                throw RuntimeException("HTTP ${response.statusCode()}: ${response.body()}")
            }
        }
    }
}

Step 3: Testing Your Code

API Parameters

This endpoint accepts the following parameters:

urlRequired(string)

Reddit post URL

Example: https://www.reddit.com/r/AskReddit/comments/ablzuq/people_who_havent_pooped_in_2019_yet_why_are_you/

cursorOptional(string)

Cursor to get more comments, or replies.

Example: ed1lvsa,ed3fnpq,ed25l2w

trimOptional(boolean)

Set to true for a trimmed down version of the response

Example: false

Run Your Code

Execute your script to test the API connection. You should see a JSON response with Reddit comments data.

✅ Success: You should receive a structured JSON response containing the requested data.

Expected Response

Here's an example of the JSON response you'll receive:

Sample Response
{
  "comments": [
    {
      "url": "https://www.reddit.com/r/AskReddit/comments/ablzuq/people_who_havent_pooped_in_2019_yet_why_are_you/ed1czme/",
      "created_utc": 1546378524,
      "created_at_iso": "2019-01-01T21:35:24.000Z",
      "subreddit_id": "t5_2qh1i",
      "approved_at_utc": null,
      "author_is_blocked": false,
      "comment_type": null,
      "awarders": [],
      "mod_reason_by": null,
      "banned_by": null,
      "author_flair_type": "text",
      "total_awards_received": 0,
      "subreddit": "AskReddit",
      "author_flair_template_id": null,
      "likes": null,
      "replies": {
        "items": [
          {
            "url": "https://www.reddit.com/r/AskReddit/comments/ablzuq/people_who_havent_pooped_in_2019_yet_why_are_you/ed1su6t/",
            "created_utc": 1546391589,
            "created_at_iso": "2019-01-02T01:13:09.000Z",
            "subreddit_id": "t5_2qh1i",
            "approved_at_utc": null,
            "author_is_blocked": false,
            "comment_type": null,
            "awarders": [],
            "mod_reason_by": null,
            "banned_by": null,
            "author_flair_type": "text",
            "total_awards_received": 0,
            "subreddit": "AskReddit",
            "author_flair_template_id": null,
            "likes": null,
            "replies": {
              "items": [
                {
                  "url": "https://www.reddit.com/r/AskReddit/comments/ablzuq/people_who_havent_pooped_in_2019_yet_why_are_you/ed1ye8p/",
                  "created_utc": 1546396468,
                  "created_at_iso": "2019-01-02T02:34:28.000Z",
                  "total_awards_received": 0,
                  "approved_at_utc": null,
                  "author_is_blocked": false,
                  "comment_type": null,
                  "awarders": [],
                  "mod_reason_by": null,
                  "banned_by": null,
                  "ups": 780,
                  "removal_reason": null,
                  "link_id": "t3_ablzuq",
                  "author_flair_template_id": null,
                  "likes": null,
                  "replies": {
                    "items": [
                      {
                        "url": "https://www.reddit.com/r/AskReddit/comments/ablzuq/people_who_havent_pooped_in_2019_yet_why_are_you/ed2xsuk/",
                        "created_utc": 1546442379,
                        "created_at_iso": "2019-01-02T15:19:39.000Z",
                        "subreddit_id": "t5_2qh1i",
                        "approved_at_utc": null,
                        "author_is_blocked": false,
                        "comment_type": null,
                        "awarders": [],
                        "mod_reason_by": null,
                        "banned_by": null,
                        "author_flair_type": "text",
                        "total_awards_received": 0,
                        "subreddit": "AskReddit",
                        "author_flair_template_id": null,
                        "likes": null,
                        "replies": {
                          "items": [],
                          "more": {
                            "has_more": false,
                            "next_cursor": null
                          }
                        },
                        "user_reports": [],
                        "saved": false,
                        "id": "ed2xsuk",
                        "banned_at_utc": null,
                        "mod_reason_title": null,
                        "gilded": 0,
                        "archived": true,
                        "collapsed_reason_code": null,
                        "no_follow": false,
                        "author": "minjabinja",
                        "can_mod_post": false,
                        "send_replies": true,
                        "parent_id": "t1_ed1ye8p",
                        "score": 332,
                        "author_fullname": "t2_nqzim",
                        "removal_reason": null,
                        "approved_by": null,
                        "mod_note": null,
                        "all_awardings": [],
                        "collapsed": false,
                        "body": "goals",
                        "edited": false,
                        "top_awarded_type": null,
                        "author_flair_css_class": null,
                        "name": "t1_ed2xsuk",
                        "is_submitter": false,
                        "downs": 0,
                        "author_flair_richtext": [],
                        "author_patreon_flair": false,
                        "body_html": "&lt;div class=\"md\"&gt;&lt;p&gt;goals&lt;/p&gt;\n&lt;/div&gt;",
                        "gildings": {},
                        "collapsed_reason": null,
                        "distinguished": null,
                        "associated_award": null,
                        "stickied": false,
                        "author_premium": false,
                        "can_gild": false,
                        "link_id": "t3_ablzuq",
                        "unrepliable_reason": null,
                        "author_flair_text_color": null,
                        "score_hidden": false,
                        "permalink": "/r/AskReddit/comments/ablzuq/people_who_havent_pooped_in_2019_yet_why_are_you/ed2xsuk/",
                        "subreddit_type": "public",
                        "locked": false,
                        "report_reasons": null,
                        "created": 1546442379,
                        "author_flair_text": null,
                        "treatment_tags": [],
                        "subreddit_name_prefixed": "r/AskReddit",
                        "controversiality": 0,
                        "depth": 3,
                        "author_flair_background_color": null,
                        "collapsed_because_crowd_control": null,
                        "mod_reports": [],
                        "num_reports": null,
                        "ups": 332
                      }
                    ],
                    "more": {
                      "has_more": true,
                      "cursor": "eduy6f3,ejxami8,eegd7xa,ef29a32,ehq4puw,eqb5cnr,edhhwh5,ei3p2wr,ej851tk,el4yhl2,epc5qyk"
                    }
                  },
                  "user_reports": [],
                  "saved": false,
                  "id": "ed1ye8p",
                  "banned_at_utc": null,
                  "mod_reason_title": null,
                  "gilded": 0,
                  "archived": true,
                  "collapsed_reason_code": null,
                  "no_follow": false,
                  "author": "[deleted]",
                  "can_mod_post": false,
                  "send_replies": true,
                  "parent_id": "t1_ed1su6t",
                  "score": 780,
                  "approved_by": null,
                  "report_reasons": null,
                  "all_awardings": [],
                  "subreddit_id": "t5_2qh1i",
                  "body": "I made my biggest poop of last year right in between Christmas and New year's- first time I could say that I filled the bowl to the waterline",
                  "edited": false,
                  "author_flair_css_class": null,
                  "downs": 0,
                  "is_submitter": false,
                  "body_html": "&lt;div class=\"md\"&gt;&lt;p&gt;I made my biggest poop of last year right in between Christmas and New year&amp;#39;s- first time I could say that I filled the bowl to the waterline&lt;/p&gt;\n&lt;/div&gt;",
                  "gildings": {},
                  "collapsed_reason": null,
                  "associated_award": null,
                  "stickied": false,
                  "subreddit_type": "public",
                  "can_gild": false,
                  "top_awarded_type": null,
                  "unrepliable_reason": null,
                  "author_flair_text_color": "dark",
                  "score_hidden": false,
                  "permalink": "/r/AskReddit/comments/ablzuq/people_who_havent_pooped_in_2019_yet_why_are_you/ed1ye8p/",
                  "num_reports": null,
                  "locked": false,
                  "name": "t1_ed1ye8p",
                  "created": 1546396468,
                  "subreddit": "AskReddit",
                  "author_flair_text": null,
                  "treatment_tags": [],
                  "collapsed": false,
                  "subreddit_name_prefixed": "r/AskReddit",
                  "controversiality": 0,
                  "depth": 2,
                  "author_flair_background_color": "",
                  "collapsed_because_crowd_control": null,
                  "mod_reports": [],
                  "mod_note": null,
                  "distinguished": null
                }
              ],
              "more": {
                "has_more": true,
                "cursor": "egos1bd,ef1lv5d,el1tr5b"
              }
            },
            "user_reports": [],
            "saved": false,
            "id": "ed1su6t",
            "banned_at_utc": null,
            "mod_reason_title": null,
            "gilded": 0,
            "archived": true,
            "collapsed_reason_code": null,
            "no_follow": false,
            "author": "jofwu",
            "can_mod_post": false,
            "send_replies": true,
            "parent_id": "t1_ed1czme",
            "score": 2415,
            "author_fullname": "t2_6ckuh",
            "removal_reason": null,
            "approved_by": null,
            "mod_note": null,
            "all_awardings": [],
            "body": "Somewhere out there, somebody has made the biggest poop of the year. And they don't even know it. ",
            "edited": false,
            "top_awarded_type": null,
            "author_flair_css_class": null,
            "name": "t1_ed1su6t",
            "is_submitter": false,
            "downs": 0,
            "author_flair_richtext": [],
            "author_patreon_flair": false,
            "body_html": "&lt;div class=\"md\"&gt;&lt;p&gt;Somewhere out there, somebody has made the biggest poop of the year. And they don&amp;#39;t even know it. &lt;/p&gt;\n&lt;/div&gt;",
            "gildings": {},
            "collapsed_reason": null,
            "distinguished": null,
            "associated_award": null,
            "stickied": false,
            "author_premium": false,
            "can_gild": false,
            "link_id": "t3_ablzuq",
            "unrepliable_reason": null,
            "author_flair_text_color": null,
            "score_hidden": false,
            "permalink": "/r/AskReddit/comments/ablzuq/people_who_havent_pooped_in_2019_yet_why_are_you/ed1su6t/",
            "subreddit_type": "public",
            "locked": false,
            "report_reasons": null,
            "created": 1546391589,
            "author_flair_text": null,
            "treatment_tags": [],
            "collapsed": false,
            "subreddit_name_prefixed": "r/AskReddit",
            "controversiality": 0,
            "depth": 1,
            "author_flair_background_color": null,
            "collapsed_because_crowd_control": null,
            "mod_reports": [],
            "num_reports": null,
            "ups": 2415
          }
        ],
        "more": {
          "has_more": true,
          "cursor": "ed1lvsa,ed3fnpq,ed25l2w,ed2bzid,ed2do8g,eda7sqp,es4scjk,edjv4rx,efp5ww0,eh8q0ke,em7lhme,epkr3k2,epu6jcz,er6c3si,errghbq,ef687ye"
        }
      },
      "user_reports": [],
      "saved": false,
      "id": "ed1czme",
      "banned_at_utc": null,
      "mod_reason_title": null,
      "gilded": 2,
      "archived": true,
      "collapsed_reason_code": null,
      "no_follow": false,
      "author": "sweatybeard",
      "can_mod_post": false,
      "send_replies": true,
      "parent_id": "t3_ablzuq",
      "score": 12211,
      "author_fullname": "t2_cep2k",
      "approved_by": null,
      "mod_note": null,
      "all_awardings": [],
      "collapsed": false,
      "body": "But when I finally do, it'll be the years biggest shit ^^^^^so ^^^^^far",
      "edited": false,
      "top_awarded_type": null,
      "author_flair_css_class": null,
      "name": "t1_ed1czme",
      "is_submitter": false,
      "downs": 0,
      "author_flair_richtext": [],
      "author_patreon_flair": false,
      "body_html": "&lt;div class=\"md\"&gt;&lt;p&gt;But when I finally do, it&amp;#39;ll be the years biggest shit &lt;sup&gt;&lt;sup&gt;&lt;sup&gt;&lt;sup&gt;&lt;sup&gt;so&lt;/sup&gt;&lt;/sup&gt;&lt;/sup&gt;&lt;/sup&gt;&lt;/sup&gt; &lt;sup&gt;&lt;sup&gt;&lt;sup&gt;&lt;sup&gt;&lt;sup&gt;far&lt;/sup&gt;&lt;/sup&gt;&lt;/sup&gt;&lt;/sup&gt;&lt;/sup&gt;&lt;/p&gt;\n&lt;/div&gt;",
      "removal_reason": null,
      "collapsed_reason": null,
      "distinguished": null,
      "associated_award": null,
      "stickied": false,
      "author_premium": false,
      "can_gild": false,
      "gildings": {},
      "unrepliable_reason": null,
      "author_flair_text_color": null,
      "score_hidden": false,
      "permalink": "/r/AskReddit/comments/ablzuq/people_who_havent_pooped_in_2019_yet_why_are_you/ed1czme/",
      "subreddit_type": "public",
      "locked": false,
      "report_reasons": null,
      "created": 1546378524,
      "author_flair_text": null,
      "treatment_tags": [],
      "link_id": "t3_ablzuq",
      "subreddit_name_prefixed": "r/AskReddit",
      "controversiality": 0,
      "depth": 0,
      "author_flair_background_color": null,
      "collapsed_because_crowd_control": null,
      "mod_reports": [],
      "num_reports": null,
      "ups": 12211
    }
  ],
  "post": {
    "approved_at_utc": null,
    "subreddit": "AskReddit",
    "selftext": "",
    "user_reports": [],
    "saved": false,
    "mod_reason_title": null,
    "gilded": 13,
    "clicked": false,
    "title": "People who haven't pooped in 2019 yet, why are you still holding on to last years shit?",
    "link_flair_richtext": [],
    "subreddit_name_prefixed": "r/AskReddit",
    "hidden": false,
    "pwls": 6,
    "link_flair_css_class": null,
    "downs": 0,
    "top_awarded_type": null,
    "hide_score": false,
    "name": "t3_ablzuq",
    "quarantine": false,
    "link_flair_text_color": "dark",
    "upvote_ratio": 0.91,
    "author_flair_background_color": null,
    "subreddit_type": "public",
    "ups": 221995,
    "total_awards_received": 0,
    "media_embed": {},
    "author_flair_template_id": null,
    "is_original_content": false,
    "author_fullname": "t2_2uhed5z4",
    "secure_media": null,
    "is_reddit_media_domain": false,
    "is_meta": false,
    "category": null,
    "secure_media_embed": {},
    "link_flair_text": null,
    "can_mod_post": false,
    "score": 221995,
    "approved_by": null,
    "is_created_from_ads_ui": false,
    "author_premium": false,
    "thumbnail": "",
    "edited": 1546379983,
    "author_flair_css_class": null,
    "author_flair_richtext": [],
    "gildings": {},
    "content_categories": null,
    "is_self": true,
    "mod_note": null,
    "created": 1546376787,
    "link_flair_type": "text",
    "wls": 6,
    "removed_by_category": null,
    "banned_by": null,
    "author_flair_type": "text",
    "domain": "self.AskReddit",
    "allow_live_comments": true,
    "selftext_html": null,
    "likes": null,
    "suggested_sort": null,
    "banned_at_utc": null,
    "view_count": null,
    "archived": true,
    "no_follow": false,
    "is_crosspostable": false,
    "pinned": false,
    "over_18": false,
    "all_awardings": [],
    "awarders": [],
    "media_only": false,
    "can_gild": false,
    "spoiler": false,
    "locked": false,
    "author_flair_text": null,
    "treatment_tags": [],
    "visited": false,
    "removed_by": null,
    "num_reports": null,
    "distinguished": null,
    "subreddit_id": "t5_2qh1i",
    "author_is_blocked": false,
    "mod_reason_by": null,
    "removal_reason": null,
    "link_flair_background_color": "",
    "id": "ablzuq",
    "is_robot_indexable": true,
    "num_duplicates": 33,
    "report_reasons": null,
    "author": "ShoddySubstance",
    "discussion_type": null,
    "num_comments": 7925,
    "send_replies": true,
    "media": null,
    "contest_mode": false,
    "author_patreon_flair": false,
    "author_flair_text_color": null,
    "permalink": "/r/AskReddit/comments/ablzuq/people_who_havent_pooped_in_2019_yet_why_are_you/",
    "stickied": false,
    "url": "https://www.reddit.com/r/AskReddit/comments/ablzuq/people_who_havent_pooped_in_2019_yet_why_are_you/",
    "subreddit_subscribers": 54408093,
    "created_utc": 1546376787,
    "num_crossposts": 73,
    "mod_reports": [],
    "is_video": false
  },
  "more": {
    "has_more": true,
    "cursor": "ed1jhoi,ed1f3kw,ed1qgjh,ed1e4vd,ed1benx"
  }
}

Verify Response Structure

Check that your response includes the expected fields:

  • ✓comments(object)
  • ✓post(object)
  • ✓more(object)

Best Practices

1

Error Handling

Implement comprehensive error handling and retry logic for failed requests. Log errors properly for debugging.

2

Caching

Cache responses when possible to reduce API calls and improve performance. Consider data freshness requirements.

3

Security

Never expose your API key in client-side code. Use environment variables and secure key management practices.

Performance Tips

Batch Requests

When scraping multiple comments, consider batching requests to maximize throughput while staying within rate limits.

Async Processing

Use asynchronous processing in Kotlin to handle multiple requests concurrently and improve overall performance.

Common Use Cases

Market Research

Analyze Reddit comments to understand market trends, competitor analysis, and audience insights.

Content Analytics

Track performance metrics, engagement rates, and content trends across Reddit comments.

Lead Generation

Identify potential customers and business opportunities throughReddit data analysis.

Troubleshooting

Common Errors

401 Unauthorized

Check your API key is correct and properly formatted in the x-api-key header.

402 Payment Required

You ran out of credits and need to buy more.

404 Not Found

The resource might not exist or be private.

500 Server Error

Temporary server issue. Implement retry logic with exponential backoff.

Frequently Asked Questions

How much does it cost to scrape Reddit comments?

ScrapeCreators offers 100 free API calls to get started. After that, pricing starts at $10 for 5k requests with volume discounts available.

Is it legal to scrape Reddit data?

Scraping publicly available data is fair game, and we only collect public data. So anything that you can see in an incognito browser is what we collect.

How fast can I scrape Reddit comments?

There is no rate limit! So you can scrape as fast as you want!

What data format does the API return?

All API responses are returned in JSON format, making it easy to integrate with any programming language or application.

Can I use this with other Kotlin frameworks?

Yes! This tutorial focuses on core Kotlin HTTP concepts that work with any framework. The API calls remain the same regardless of your specific Kotlin setup.

How do I handle large datasets?

For large datasets, implement pagination, use streaming responses where available, and consider storing data in a database for efficient querying.

Related Tutorials

All Tutorials

Browse all available scraping tutorials for different platforms and languages.

Free Tools

Try our free online tools to test scraping without writing any code.

Ready to Start Scraping?

Get started with 100 free API calls. No credit card required.

Start Scraping ⚡️ View Documentation