How many writing samples do you need to build a voice profile?
150 words minimum. 1,000 words for a strong profile. Here is how sample size affects accuracy and what kind of samples work best.
The short answer: 150 words minimum in a single style category. That is enough for a basic profile. More is better.
The thresholds
150 words. The minimum for a usable profile. At this level, the system can identify your broad patterns: general sentence length tendencies, most common vocabulary, and basic structural habits. The output will be in the right neighborhood but might miss your subtler patterns.
500 words. A solid profile. Your sentence rhythm distribution becomes clearer. Vocabulary frequency tiers start separating (which words you use often vs. rarely). Punctuation habits emerge. The output sounds noticeably more like you.
1,000+ words. A strong profile. The system has enough data to distinguish your core register from your signature phrases from your rare emphasis words. Structural patterns (how you open, how you close, paragraph length) are well-defined. The output feels natural.
5,000+ words. The profile starts to feel like the system has read everything you have written. Subtle patterns emerge: your specific way of transitioning between ideas, your paragraph-level rhythm, the precise frequency of your filler phrases.
What kind of samples work best
Natural writing beats polished writing. The goal is your patterns, not your best writing. Emails, messages, notes, and first drafts capture your actual habits. Published, heavily-edited pieces carry the editor's patterns mixed with yours.
Variety of context helps. Samples from different situations (a quick email, a longer report, a personal note) give the system a fuller picture of your range within a register.
Avoid AI-assisted writing. Samples written with AI help carry the model's patterns mixed with yours. Use writing you produced entirely on your own.
Does it improve over time?
Yes. In Yourtone, every rewrite you approve feeds back into your profile. After every three approved rewrites, the system re-analyzes to incorporate the new evidence. Your profile gets sharper with use, even without adding new samples.
The combination of initial samples plus ongoing feedback produces the best results. Start with what you have. Use the tool. Approve what sounds right. The profile converges.