# What is the most popular feed format: rss, atom, or JSON?

**URL:** <https://discuss.httparchive.org/t/what-is-the-most-popular-feed-format-rss-atom-or-json/2577>\
**Category:** Analysis\
**Created:** [May 26, 2023, 2:59pm UTC](https://discuss.httparchive.org/t/what-is-the-most-popular-feed-format-rss-atom-or-json/2577 "2023-05-26T14:59:27Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![rviscomi](https://yyz1.discourse-cdn.com/flex035/user_avatar/discuss.httparchive.org/rviscomi/32/835_2.png) [@rviscomi](https://discuss.httparchive.org/u/rviscomi)\
**Post date:** [May 26, 2023, 3:16pm UTC](https://discuss.httparchive.org/t/what-is-the-most-popular-feed-format-rss-atom-or-json/2577/2 "2023-05-26T15:16:50Z")

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Hi @pawelgrzybek, welcome to the HTTP Archive community! 👋

The size of the dataset may seem intimidating at first, but there are a few techniques to minimize the amount of processing and costs involved.

- Use the `httparchive.all.requests` table with `WHERE is_main_document` set to ignore everything that’s not an HTML response
- Use `WHERE is_root_page` to ignore secondary pages, which I’m guessing are usually similar to home (root) pages in terms of feed metadata
- Use `WHERE client = 'mobile'` (or `'desktop'`) assuming there are no major differences between clients
- Use `TABLESAMPLE` to reduce the number of rows processed, ie `TABLESAMPLE SYSTEM (10 PERCENT)` will “only” process 234 GB (everyone gets 1 TB free per month)
- Set up cost controls to ensure you never pay a cent out of pocket unexpectedly

All that said, here’s a query you can run that is 234 GB and will give you a sample of ~10% of pages:

```sql
WITH pages AS (
  SELECT
    REGEXP_EXTRACT_ALL(response_body, r'(?i)(application/rss\+xml|application/atom\+xml|application/feed\+json)') AS feed_types
  FROM
    `httparchive.all.requests` TABLESAMPLE SYSTEM (10 PERCENT)
  WHERE
    date = '2023-05-01' AND
    client = 'mobile' AND
    is_main_document AND
    is_root_page
)

SELECT
  LOWER(feed_type) AS feed_type,
  COUNT(0) AS pages
FROM
  pages
LEFT JOIN
  UNNEST(feed_types) AS feed_type
GROUP BY
  feed_type
ORDER BY
  pages DESC

```

Here are the results:

| feed\_type | # pages | % pages |
| --- | --- | --- |
| `application/rss+xml` | 1,214,353 | 50% |
| _(none)_ | 1,045,274 | 43% |
| `application/atom+xml` | 189,469 | 8% |
| `application/feed+json` | 112 | 0% |

So if the sample is representative, we can say that RSS is used by 50% of pages, Atom on 8%, and JSON Feed on \<1%. And about 58% of pages use any feed type at all.

Hope that helps!

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_[View the full topic](https://discuss.httparchive.org/t/what-is-the-most-popular-feed-format-rss-atom-or-json/2577)._