What are uid, mid and bid on Weibo?

Weibo uses three identifiers, and two of them are the same number in different clothes. The uid names an account. The mid names a post. The bid is that post's mid encoded in base62, and it is what you see in a post's address: in weibo.com/6082913457/Qkz3PvVLT, the first part is the author's uid and the second the bid.

The three side by side

	uid	mid	bid
Names	An account	A post	A post
Shape	Digits, usually 10	Digits, 16 for current posts	9 characters from 0-9, a-z, A-Z
Example	6082913457	5249013377610245	Qkz3PvVLT
Seen in	weibo.com/u/<uid>, every author object	Web and app JSON (mid, idstr)	Post URLs (mblogid in web JSON)

The names are not used consistently. In Weibo's web and app JSON, mid is the numeric string and the short code is mblogid. In the documentation of the official API, id is the number and "mid" is the base62 form: statuses/querymid turns a numeric id into a code such as 8Ras3qlz, and statuses/queryid goes back. When a tool asks for a "mid", check whether it wants digits or letters.

Converting mid to bid

Split the numeric mid into groups of 7 digits from the right. Write each group in base62 with the alphabet 0-9a-zA-Z and pad it to 4 characters, except the leftmost group. Join the pieces.

Worked example for 5249013377610245: the groups are 52, 4901337 and 7610245; in base62 they are Q, kz3P and vVLT; joined, Qkz3PvVLT. Going back, split the bid into 4-character groups from the right, decode each and pad to 7 digits. We checked the method against six real posts whose numeric mid and link code we had from the same response; all six matched.

What okdata takes and returns

Endpoint	Takes	Returns	Cost
Weibo post search	query	id = mid, url = weibo.com/uid/bid, author.id = uid	$0.002 a page
Weibo account profile	id = numeric uid	the account, with id = uid	$0.002

author.username holds the account's custom address (个性域名) when it has one, the part after weibo.com/ in a link like weibo.com/somebrand. The profile endpoint does not accept it; use the numeric author.id.

Example

import os, requests

ALPHA = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"

def mid_to_bid(mid: str) -> str:
    parts, end = [], len(mid)
    while end > 0:
        start = max(0, end - 7)
        n, code = int(mid[start:end]), ""
        while n:
            n, r = divmod(n, 62)
            code = ALPHA[r] + code
        parts.insert(0, code.rjust(4, "0") if start else code or "0")
        end = start
    return "".join(parts)

assert mid_to_bid("5249013377610245") == "Qkz3PvVLT"

body = requests.get("https://api.okdata.online/v1/weibo/posts/search", timeout=60,
    headers={"Authorization": f"Bearer {os.environ['OKDATA_API_KEY']}"},
    params={"query": "新品发布", "fields": "id,url,author.id,author.username"}).json()
for p in body["data"]["items"]:
    print(p["author"]["id"], p["id"], mid_to_bid(p["id"]), p["url"])

Limits

• Keep mids and uids as strings. A 16-digit mid is beyond the 15 digits Excel keeps, and JavaScript code should not do arithmetic on it.
• There is no Weibo post-by-ID endpoint in the catalog. A mid or bid tells you which post it is, but you reach posts here through search.
• The uid stays the same when the nickname changes, so key accounts on the uid rather than on a name or a custom address.

For profile numbers from a uid, see getting a Weibo user's followers from their UID.