Do trending boards sync? 6 platforms, 8 days

Findings

• They do not sync. In 8 days no topic reached all 6 platforms. The widest, the US midterm elections, reached 5 (not Xiaohongshu).
• Identical titles are almost absent. Of 1,078 distinct titles, only 6 matched word for word across platforms, all among Douyin, Weibo and Bilibili.
• The Chinese platforms share a layer of topics. Douyin–Bilibili 27.4%, Douyin–Weibo 27.3%, Weibo–Bilibili 21.8%. Xiaohongshu shares only 6–11% with them.
• That layer leans on big events. Without one esports tournament (League of Legends S16), Douyin–Bilibili falls to 13.9% and Weibo–Bilibili to 8.8%; Douyin–Weibo stays at 21.0%.
• X, Reddit and the Chinese platforms rarely meet. X and the Chinese platforms share only 10 topics, mostly match results and world news. Of Reddit’s 54 titles, only 2 match another platform.
• Titles change in a day; topics last longer. Under 3% of the titles on Weibo, Douyin, X and Reddit are still on the board the next day. A topic can stay under new titles: the tournament was on Bilibili’s board all 8 days.

Topic overlap between each pair of platforms

Overlap = (A’s titles whose topic is also on B + B’s titles whose topic is also on A) ÷ (A’s titles + B’s titles). For Douyin–Bilibili: (42 + 76) ÷ (228 + 203) = 27.4%.

How many of a platform’s titles have the same topic on another platform within a day: Bilibili 41.4% (84/203), Weibo 39.5% (94/238), Douyin 30.3% (69/228), X 24.3% (57/235), Xiaohongshu 13.3% (16/120), Reddit 3.7% (2/54). Together 322 of 1,078, or 29.9%.

Of the 51 topics, 45 reached at least 2 platforms within a day: 30 reached 2, 11 reached 3, 3 reached 4, 1 reached 5, none reached 6.

How long an entry stays

This uses only the 7 days from 10-30 to 11-05, read 24 hours apart. “Still there next day” needs an identical title; Reddit is matched by post link. A “run” is an unbroken stretch on the board, leaving out runs already there on the first day or still there on the last, whose start or end we cannot see.

Similar titles: one contains the other (at least 4 characters), or they share at least half of their two-character pieces. The numbers barely move when this is allowed, so the churn is not just rewording. Xiaohongshu is the exception: half of its top 10 (30/60) are still there the next day, and its longest entry was on the board for 7 days.

Topics outlive titles. In the examples below, “days on the board” counts the days of the 8 with a title on that topic, not necessarily in a row:

The midterms are the only cross-language topic in the window that shows an order, and one example does not show which platform comes first in general.

The data

• 48 boards, one per platform per UTC day, all read successfully.
• 1,175 entries: X 240, Reddit 55, Xiaohongshu 160, Douyin 240, Weibo 240, Bilibili 240. That is 1,078 distinct titles, removing repeats within a platform.
• Entries per board: 30 each on X, Douyin, Weibo and Bilibili (this site keeps the first 30), 20 on Xiaohongshu, 6–7 on Reddit.
• Read at: UTC 00:00–00:10 from 10-30 on (about 8 am in Beijing). The 10-29 boards were read at UTC 10:38–11:08, about 13 hours before the next, so they are left out of the time on the board.

How “the same topic” was decided

Two levels, because plain character matching is not enough.

1. Same title. Identical after normalising case and full-width characters and removing punctuation, within one day. This is objective, but it finds only 6 titles and cannot see the same event in two languages.
2. Same topic. We first listed title pairs within a day that share three Chinese characters in a row or a Latin word (308 pairs), then read all 1,175 entries and wrote 51 matching rules for the same event, work, tournament or the running story of one person. English and Japanese terms on X were matched to Chinese topics by meaning.

The second level is a judgement, not a measurement. Widen or narrow a rule and the overlap changes. A tournament’s matches count as one topic, so tournament figures run high.

Limits

• Only 8 days. The window happens to hold an esports tournament and a US election, so it is not an ordinary week. A longer window may change these findings.
• One read a day. What rises and falls within a day goes unseen. “One day” means seen by one read, not alive for only 24 hours.
• The boards differ. X lists terms, Reddit lists posts, and the Chinese platforms mostly list short topic phrases. Reddit has 6–7 entries a day, so one entry moves its percentages a lot.
• X’s board here is the worldwide one. Of its 240 entries, 71 are in Japanese or Chinese characters, 7 in Arabic and 1 in Korean, with many campaign tags. The site’s board moved to the US list only on 2026-11-06, so read X’s overlap here as the worldwide list, not any one country.
• X’s figures run high. One event takes many terms on X: the Manchester United match took 12, and all of them count as matched.
• Cross-language matching is by reading. The topics shared between X, Reddit and the Chinese platforms were matched by meaning, so some are missed and some may be wrong.
• No TikTok or YouTube. These two are not among our daily boards.

What this is good for

• One platform’s board misses most of what is on the others, so read several when choosing topics or watching a brand.
• Compare platforms by topic, not by title. Word-for-word matching finds almost nothing in this data.
• To tell whether something is still hot, look for the topic, not for a title. Outside Xiaohongshu, titles have mostly changed by the next day.

Reading the boards again costs 26 credits a day (X 6, Xiaohongshu 12, Reddit, Douyin, Weibo and Bilibili 2 each), or 208 credits for 8 days, at the catalog of 2026-11-05. Today’s boards are on the daily trending page.