Every learner hits this fork early. The short answer: pick the script of the place your Chinese is for, learn it well, and let the second script arrive almost for free through reading. Here is the longer version.
Who writes what
Simplified (简体字) is the script of mainland China, Singapore and Malaysia - the product of 1950s-60s reforms that cut stroke counts on about 2,000 characters: 學→学, 體→体, 龍→龙. Traditional (繁体字) survives intact in Taiwan, Hong Kong, Macau and much overseas-Chinese print. Same language, two character sets; the grammar and most vocabulary are identical either way.
How different are they, really?
Less than they look. Most simplifications follow a handful of systematic rules - 言→讠 on the left of compounds, 貝→贝 for money characters, 麥→麦 - and once you have seen a component simplified once, you have seen it everywhere. The genuinely arbitrary cases (發→发, 麵→面) are a few hundred, not thousands. Compare 龍/龙 or 學/学 side by side - the skeleton usually survives.
The vocabulary diverges more than the script: Taiwan says 软体 for software where the mainland says 软件, 计程车 where the mainland says 出租车. The Taiwan vs Mainland table lists the differences that actually matter.
So which one first?
Going to mainland China, or taking the HSK? Simplified. Taiwan, TOCFL or heritage family characters? Traditional. Genuinely undecided? Most learners start Simplified - the materials ecosystem is larger - then add Traditional reading later, which costs a weekend of exposure per hundred characters, not a second education.
Learning both without doubling the work
LinZi runs the two scripts as parallel first-class tracks, not a display flag: the same 12,500-word curriculum, the same 1,760 stories, zh-CN or zh-TW audio - you flip a toggle and every card, story and dictionary page renders in the other script. Studied vocabulary carries over, so learning to read the other script is the only new job - and reading is exactly what the script switch drills.
Common questions
Is Traditional Chinese harder to learn than Simplified?
More strokes per character, so slower to handwrite - but recognition difficulty is similar, and Traditional keeps phonetic/semantic components that Simplified sometimes erases.
Can I switch from Simplified to Traditional later?
Yes - most learners report reading Traditional comfortably after a few weeks of exposure, because ~80% of simplifications are systematic. Writing takes longer.
Do Duolingo and most apps teach Traditional?
Most major apps are Simplified-only or treat Traditional as a display option. A real Traditional track needs zhuyin, zh-TW audio and the TOCFL/MOE vocabulary - see our Taiwan guide for the full stack.