YouTube Comments API: How to Fetch Comments Programmatically in 2026

The Official API

How does commentThreads.list work?

A comment thread in the YouTube Data API v3 is a top-level comment plus its replies, and commentThreads.list is the endpoint that fetches them for a video. The endpoint:

GET https://www.googleapis.com/youtube/v3/commentThreads
  ?part=snippet,replies
  &videoId=VIDEO_ID
  &order=relevance
  &maxResults=100
  &key=YOUR_API_KEY

Key parameters

The response shape that matters

Each item in the response is a commentThread resource. The fields you'll actually use:

Pagination

Each page returns at most 100 threads. The response carries a nextPageToken while more pages exist; pass it back as pageToken on the next request, and stop when the token disappears. Each page is a separate API call (1 quota unit each).

comments.list — full reply threads

part=replies on commentThreads only includes up to 5 replies per thread. When a thread's totalReplyCount is higher than what came back inline, fetch the rest with comments.list, passing the top-level comment's ID as parentId:

GET https://www.googleapis.com/youtube/v3/comments
  ?part=snippet
  &parentId=TOP_LEVEL_COMMENT_ID
  &maxResults=100
  &key=YOUR_API_KEY

Do you need OAuth to read YouTube comments?

Reading public YouTube comments does not require OAuth — a plain API key is enough. OAuth 2.0 is only needed for write operations: posting, replying, editing, or moderating.

Gotchas

Five things that bite in production

The YouTube comments API has a handful of behaviors that surprise developers the first time a pipeline hits them — disabled comments, quota math, HTML-encoded text, and pagination limits.

The Simpler Alternative

How does the OutlierKit comments endpoint differ?

The OutlierKit API is a YouTube competitive-intelligence API that returns outlier scores, semantic channel search and similarity, video transcripts, comments, and keyword search volumes as structured JSON — one bearer-token key, 1 credit per call, on OutlierKit Pro ($49/month) and Max ($199/month) plans. If your use case is research — not posting or moderating — its comments endpoint skips the Google Cloud project entirely:

GET https://outlierkit.com/api/v1/videos/:videoId/comments

• Always live from YouTube — comments are never cached (the response's source field is always "live").
• sort: top or newest; limit: 1–100, default 30.
• 1 credit per call, like every OutlierKit endpoint.

Example call

curl -X GET 'https://outlierkit.com/api/v1/videos/nSM1m7Q8gkg/comments?sort=top&limit=20' \
  -H 'Authorization: Bearer <your_api_key>'

Response shape

{
  "comments": [
    {
      "commentId": "...",
      "author": "@viewerhandle",
      "authorChannelId": "UC...",
      "text": "This is exactly what I needed, part 2 please!",
      "likes": 412,
      "replies": 18,
      "publishedTime": "2 weeks ago",
      "publishedAt": "2026-05-28T14:03:00Z",
      "isChannelOwner": false,
      "isVerified": false,
      "isCreator": false
    }
  ],
  "totalCount": 1843,
  "returned": 20,
  "source": "live"
}

Why it's convenient

• Bearer token, no Google Cloud project — generate a key from your OutlierKit dashboard and you're calling in under a minute. No console setup, no quota dashboard, no OAuth screens.
• Flags pre-parsed — isCreator, isChannelOwner, and isVerified come ready to filter on, so isolating creator replies or stripping the channel's own pinned comment is one line, not a join against channel IDs.
• Pairs with transcripts in one API — GET /videos/:videoId/transcript lives on the same base URL behind the same token, so the comments-plus-transcript audience-signal workflow is two calls with one auth setup. See the transcript API guide.

Full request/response reference in the live API docs. API access is included on Pro ($49/mo, 500 credits) and Max ($199/mo, 2,000 credits) — credits are shared with the web app, with top-ups at $10 per 100.

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