Two official standards cover Mandarin proficiency: the HSK, mainland China's test in Simplified characters, and the TOCFL (华语文能力测验), Taiwan's test in Traditional. Picking one is mostly picking where your Chinese is for - but the vocabularies diverge enough that the list you study matters as much as the certificate.
How the levels map
TOCFL's vocabulary list, the 华语八千词 ("eight thousand words"), has a Novice band (levels 1-2, ~1,000 words) then five levels to ~8,000. Against HSK 3.0, Novice-TOCFL ≈ HSK 1-2, TOCFL 1-2 ≈ HSK 3-4, TOCFL 3-4 ≈ HSK 5-6, TOCFL 5 ≈ the lower 7-9 band. Rough, but close enough to plan with.
Same language, different words
The tests reflect real usage: Taiwan writes 计程车 for taxi where the mainland writes 出租车, 软体 for software where the mainland writes 软件, and reads 和 as hàn where the mainland reads hé. A sizeable slice of everyday vocabulary differs - see the Taiwan vs Mainland reference - so a HSK-perfect student lands in Taipei missing real words, and vice versa.
Which one for you
Study, work or live in Taiwan: TOCFL - it is what Taiwanese universities and employers recognize, and it is written in Traditional. Mainland university admissions, the Confucius-Institute ecosystem, or no Taiwan plans: HSK. Unsure? Learn whichever vocabulary list your life points to first; the scripts and readings transfer better than the paperwork.
Both full lists are here - TOCFL vocabulary lists (Novice 1-2 and levels 1-5) and HSK 3.0 lists - every entry linking a dictionary page like 垃圾, which is itself a famous divergence: lājī in Beijing, lèsè in Taipei.
Common questions
Is TOCFL harder than HSK?
Comparable difficulty band-for-band. The real difference is the script (Traditional) and the vocabulary - learners who only studied mainland wordlists find TOCFL reading sections harder than the level suggests.
Can I take TOCFL in Simplified characters?
No - TOCFL is a Traditional-script exam. If you cannot read 繁体 at speed, the reading sections are the bottleneck, not the grammar.
Which is more recognized internationally?
HSK is the more widely administered test globally; TOCFL is the standard inside Taiwan and increasingly offered abroad through Taiwan's overseas Mandarin centers.