Simplified or Traditional?
To a search engine, Simplified and Traditional characters are different strings: 优化 and 優化 both mean "optimise", but a page written in one is not an exact match for a query typed in the other. Choose the script your readers use. Singapore and Malaysia use Simplified characters; Taiwan and Hong Kong use Traditional.
If you need both, publish them as separate pages with their own URLs, connect them with hreflang (for example zh-SG and zh-TW) and adapt the vocabulary, not just the characters.
Regional vocabulary matters
The same thing can have different everyday names across Chinese-speaking regions. A taxi is 德士 in Singapore and Malaysia, 出租车 in mainland China, 計程車 in Taiwan and 的士 in Hong Kong. A wet market in Singapore is often 巴刹, from the Malay "pasar". People search with the words they use, so a Singapore page written with mainland vocabulary can miss the local query.
Before writing, look at the live results for your main keyword from the country you are targeting and note the terms the top pages use.
Keywords without spaces
- Search engines split Chinese text into words with segmentation algorithms, so a phrase like 搜索引擎优化 can match queries for its parts as well as the whole.
- Counting "words" does not work the way it does in English. Word counters and keyword-density checks that split on spaces undercount Chinese text; measure length in characters instead.
- Short head terms are very competitive. Longer, specific questions (for example adding a city, a product type or 怎么 "how") are easier to rank for and closer to purchase intent.
Titles, descriptions and URLs
- Google truncates titles and descriptions by pixel width, and Chinese characters are wider than Latin letters, so a Chinese title fits in roughly half the characters of an English one. Put the keyword first.
- Chinese characters in URLs are percent-encoded: each character becomes nine characters such as %E4%BC%98, so links become long and hard to share. Most sites use English or pinyin slugs for Chinese pages.
- Set the page language correctly (lang="zh-Hans" or a region such as zh-SG) so browsers and search engines handle the text properly.
Google or Baidu?
If your readers are in Singapore, Malaysia, Taiwan, Hong Kong or the wider diaspora, Google is the main engine and normal SEO practice applies. Mainland China is different: Google Search is not accessible there, Baidu leads, and serious Baidu SEO usually involves hosting in mainland China, which requires an ICP licence, plus Baidu's own webmaster tools. LazySEO does not handle any of that.