# What is __biz in a WeChat article link?

> __biz is the Official Account's ID in WeChat web links: a Base64 string that decodes to a number and is the same on every article of the account. Where it appears and how APIs relate to it.

Canonical page: https://okdata.online/answers/wechat-biz-parameter/

**Short answer: **__biz identifies the Official Account that published the article: a Base64 string such as MzA5NTI3MjIwMA==, the same on every article from that account, that decodes to a plain number. Short /s/ links do not show it. okdata's article detail takes either link form for $0.02 and returns the account's gh_ ID; Official Account search returns __biz itself as ext.biz.

Open a WeChat article in a browser and the long form of its address looks like `mp.weixin.qq.com/s?__biz=MzA5NTI3MjIwMA==&mid=2650412873&idx=1&sn=…`. The first parameter, `__biz`, says which Official Account published it. Every article from that account carries the same value, and so does the account's profile page link (`mp.weixin.qq.com/mp/profile_ext?action=home&__biz=…`). That is why older scrapers and RSS tools ask for "the biz": it is the only account identifier that sits in plain sight in a web link.

## What it looks like

- A Base64 string, almost always 16 characters ending in `==`, such as `MzA5NTI3MjIwMA==`. In links copied out of HTML or other URLs it may appear percent-encoded, as `MzA5NTI3MjIwMA%3D%3D`.
- Decode it and you get a decimal number: `MzA5NTI3MjIwMA==` is `3095272200`. The number has no other public use; keep the Base64 form, which is what every tool expects.
- It never appears in the short form of a link, `mp.weixin.qq.com/s/` followed by a short code. Both forms open the same article; see [mid, idx and sn](/answers/wechat-article-link-mid-idx-sn/) for the rest of the long form.

## How it differs from the other account IDs

| ID | Looks like | Where you see it |
|---|---|---|
| `__biz` | `MzA5NTI3MjIwMA==` | Long article links, profile links |
| Original ID | `gh_` + 12 hex characters | Account settings, page source, APIs |
| WeChat ID | a short handle such as `brand_news` | The account's profile in WeChat |

None can be computed from another. You map them by looking them up; [finding an account's IDs](/answers/find-wechat-official-account-id/) covers that from a name.

## How the API relates to it

- [Official Account article detail](/apis/wechat_mp/articles/get/) takes a short or long article link. It returns the full text and `author.id`, the account's original ID (gh_…). The `url` it returns is normally the long form, from which you can read `__biz`.
- [Official Account article history](/apis/wechat_mp/accounts/articles/list/) takes the original ID or WeChat ID, not `__biz`. Each article's `url` in the list is a long link with `__biz` in it.
- [Official Account search](/apis/wechat_mp/accounts/search/) with `view=full` returns `ext.biz` for each account found, and `url` is the profile link built from it.

| Task | Calls | Cost |
|---|---|---|
| One article link to full text and gh_ ID | 1 | $0.02 |
| One account name to gh_ ID and biz | 1 | up to $0.58, $0.058 per account found |
| Latest 10 articles by gh_ ID | 1 | $0.02 |

## Example: read __biz from any article link

```python
import base64, os, requests
from urllib.parse import urlparse, parse_qs

r = requests.get("https://api.okdata.online/v1/wechat_mp/articles/get",
                 headers={"Authorization": f"Bearer {os.environ['OKDATA_API_KEY']}"},
                 params={"url": "https://mp.weixin.qq.com/s/k3Vq8ZtYwLr2PxN0aHd5Fg",
                         "fields": "id,url,title,author.id,author.name"},
                 timeout=60)
item = r.json()["data"]["item"]
biz = parse_qs(urlparse(item["url"]).query).get("__biz", [None])[0]
print(item["author"]["id"], biz, base64.b64decode(biz).decode() if biz else None)
```

## Limits

- An account that went through WeChat's account migration ends up with new IDs; look it up again rather than trusting an old biz.
- Deleted articles return `not_found`, which is not charged.
- Getting the article text itself is covered in [full text from a mp.weixin.qq.com link](/answers/wechat-article-full-text-from-link/).

## Endpoints used

- [Official Account article detail](https://okdata.online/apis/wechat_mp/articles/get/) `wechat_mp.articles.get`: $0.02 per call
- [Official Account article history](https://okdata.online/apis/wechat_mp/accounts/articles/list/) `wechat_mp.accounts.articles.list`: $0.02 per call · about 10 articles per page
- [Official Account search](https://okdata.online/apis/wechat_mp/accounts/search/) `wechat_mp.accounts.search`: $0.058 per account · at most $0.58 per call

## More about WeChat Official Accounts

- [WeChat Official Accounts API](https://okdata.online/apis/wechat_mp/)
- [WeChat Official Account API in Python for RAG (2026)](https://okdata.online/guides/wechat-official-account-api-python/)
- [How to get a WeChat Official Account's articles and full text](https://okdata.online/guides/wechat-official-account-articles/)
- [Why can't ChatGPT or Claude read a WeChat article link, and how do I fix it?](https://okdata.online/answers/ai-read-wechat-article-link/)
- [How do I export all articles of a WeChat Official Account without logging in?](https://okdata.online/answers/export-wechat-official-account-articles/)
- [How do I monitor competitors' WeChat Official Accounts for new articles?](https://okdata.online/answers/monitor-competitor-wechat-official-accounts/)
- [What is a WeChat Official Account's original ID (gh_…)?](https://okdata.online/answers/wechat-gh-original-id/)
- [How much does a WeChat Official Account article API cost?](https://okdata.online/answers/wechat-official-account-api-price/)
- [Official platform APIs vs third-party data APIs (2026)](https://okdata.online/compare/official-apis-vs-data-apis/)
- [MCP servers for social media data: self-hosted vs hosted](https://okdata.online/compare/social-media-data-mcp-servers/)
- [WeChat article APIs: official vs third-party vs open-source (2026)](https://okdata.online/compare/wechat-article-data-apis/)
- [Ways to get WeChat Official Account data: the official API, RSS bridges and data APIs](https://okdata.online/compare/wechat-official-account-data-apis/)
- [Xiaohongshu, Douyin and WeChat MCP servers: self-hosted vs hosted](https://okdata.online/compare/xiaohongshu-douyin-wechat-mcp-servers/)
- [Account posts API](https://okdata.online/roles/accounts-posts-list/)

## Sources

- [V2EX: a WeChat article is identified by biz + mid + idx, and mid is unique within one account](https://www.v2ex.com/t/474105) (read 2026-11-12)
- [ClearURLs rules: a WeChat article link only needs __biz, mid, idx and sn (issue #13)](https://github.com/ClearURLs/Rules/issues/13) (read 2026-11-12)

Where people asked this (read 2026-11-12): 

- https://github.com/chyroc/WechatSogou/issues/308
- https://github.com/wnma3mz/wechat_articles_spider/issues/5

Updated 2026-11-12