Found an API endpoint that returns actual YT dislike count

[Theta-Dev]

Today I wanted to search YouTube comments using the tool https://ytcomment.kmcat.uk. For some reason, this tool did not work. Clicking the search comments button had no effect. But when I opened the devtools to check what's wrong with it, I found something interesting. The web app directly accesses the YouTube API which returns actual dislike counts.

Note that when making requests to it, you have to set the Referer header, otherwise you will be blocked.

curl -H "Referer: https://ytcomment.kmcat.uk/" "https://www.googleapis.com/youtube/v3/videos?part=statistics&id=0-wPm99PF9U&key=AIzaSyCOUG9NmlrerQC5OnS3Erbh5K34PobYDQE"

{
  "kind": "youtube#videoListResponse",
  "etag": "oImreHEbmn_nR9OlNMA5Cp8XrkA",
  "items": [
    {
      "kind": "youtube#video",
      "etag": "TrswGlW40k_I9ZUGNP5zJCYmLGw",
      "id": "0-wPm99PF9U",
      "statistics": {
        "viewCount": "14005678",
        "likeCount": "632101",
        "dislikeCount": "160972",
        "favoriteCount": "0",
        "commentCount": "153109"
      }
    }
  ],
  "pageInfo": {
    "totalResults": 1,
    "resultsPerPage": 1
  }
}

So I logged into the YouTube developer page and checked if they - against all odds - reenabled the dislike count on their API. Obviously they did not, this was the response I got from the same video:

{
  "kind": "youtube#videoListResponse",
  "etag": "iCh1zkrk-lUo6t-AsB-TWvHOpis",
  "items": [
    {
      "kind": "youtube#video",
      "etag": "m4p3DUOR-oA87w_aiVgU8agne5c",
      "id": "0-wPm99PF9U",
      "statistics": {
        "viewCount": "14005678",
        "likeCount": "632098",
        "favoriteCount": "0",
        "commentCount": "153475"
      }
    }
  ],
  "pageInfo": {
    "totalResults": 1,
    "resultsPerPage": 1
  }
}

Now I have some questions...

Does anyone have an idea why this works? Does the owner of ytcomment have an older account/api key, so they allow them to use an older version of the API so their application does not break? I think I read about developers being able to specifically apply for dislike access, but this application only extracts and searches comments, so why should the owner have applied for that?

Could any YouTuber verify this data? I mean it is coming directly from YouTube's server, so it should be genuine, but verifying it won't hurt.

If these numbers are correct, there is a huge discrepancy between the RYD data and the actual dislike count for some videos. The video I checked is Disney's new Little Mermaid trailer. There was even a Daily Mail article about how many dislikes it got, so I had to verify. RYD shows 1.751.512 dislikes vs. only 160.972 according to this YouTube API.

[sy-b]

That is amazing discovery!
My best guess is that YT accepted the dev's request for exemption

I don't think that this API key should be in public.
Although it is possible to find it out from ytcomment.kmcat.uk, I would not want YT or more people noticing (& possibly exploiting) it.
YT clearly states here - "Developers who do not display dislike counts publicly and still need the dislike count for their API client can apply to be put on an allow list for an exemption."

[notune]

I tested it on one of my old videos, that got 96 dislikes showing in youtube studios (the addon shows 97, so in this case it's accurate) and when calling the value with the api
curl -H "Referer: https://ytcomment.kmcat.uk/" "https://www.googleapis.com/youtube/v3/videos?part=statistics&id=GjufmqghcyA&key=AIzaSyCOUG9NmlrerQC5OnS3Erbh5K34PobYDQE"
the same dislike-count is returned:

{
  "kind": "youtube#videoListResponse",
  "etag": "oUlGwvF573fixib2-VUfBWXuNWE",
  "items": [
    {
      "kind": "youtube#video",
      "etag": "ClY0IT69qpJqTv8xQcDPNqmjADY",
      "id": "GjufmqghcyA",
      "statistics": {
        "viewCount": "159801",
        "likeCount": "554",
        "dislikeCount": "96",
        "favoriteCount": "0",
        "commentCount": "97"
      }
    }
  ],
  "pageInfo": {
    "totalResults": 1,
    "resultsPerPage": 1
  }
}

so I can confirm that the API is working properly. Also noticed that a lot of videos had a lot more dislikes in the addon than from what the API returns: For example this video, in which Biden says the pandemic is over, gets 1221 dislikes in the addon, but has only 326 according to the API. Thats 3.7x more..