Writing that is clear, direct, and appropriate to the audience — free of jargon, passive voice, and unnecessarily complex sentence structures. In UX, plain language reduces cognitive load and ensures all users, regardless of reading level, can understand interface text.
Common contexts
- Rewriting a legal consent screen from passive-voice legalese into two plain sentences a non-expert can act on
- Auditing all error messages in a banking app to replace technical codes like 'Error 403' with actionable plain descriptions
- Replacing internal product terminology in a SaaS dashboard with the words customer support logs show users actually say
Use when
Apply plain language rigorously in error messages, onboarding instructions, consent flows, and any text a user encounters under stress or time pressure — these are the moments where confusing copy causes real task failure.
Avoid when
Don't oversimplify interface copy for expert users who rely on precise technical terminology to make decisions — replacing 'MIME type' with 'file format type' in a developer tool can introduce ambiguity where the jargon was actually the clearest option.
The test for plain language isn't whether a non-expert can parse the sentence — it's whether the right user can act on it in under five seconds without re-reading.
Real-world examples
- Monzo's banking app replaced standard financial language ('insufficient funds transaction declined') with 'You don't have enough money for this payment' — a plain-language switch that cut support contacts about declined cards by 25%.
- GOV.UK's writing guide bans words like 'facilitate', 'leverage', and 'synergy', requiring civil servants to write at a Grade 9 reading level; readability testing showed form completion rates improved measurably after the switch.
- MailChimp's Content Style Guide has been widely adopted as an industry reference for plain-language writing in product, not just because it's good guidance but because Mailchimp publishes it openly and links to it from their brand page.