Plain language checker
Checks whether a reader whose first language isn't English will get through your text: rare vocabulary, idioms, and phrasal verbs whose meaning can't be guessed from their parts.
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Paste a document above to see which words and phrases might be hard for a non-native reader.
Words that are fine in your context (allowlist)
One word or phrase per line. Every technical document has necessary jargon — add yours here so it stops getting flagged. Saved in this browser only.
Your text, annotated
Worth a look — select a highlight for details. Nothing here is flagged as outright wrong.
Findings
What this checks
This is a readability checker that explains itself in words instead of a number — the same idea behind why readability formulas fail, applied to the specific question of whether a non-native reader will follow along. A grade-level score can't tell you that "utilize" is harder to recognize than "use," or that "touch base" means nothing if you translate it literally. This can.
Rare vocabulary
Every word is checked against a combined list of the most common general and academic English words — the New General Service List and New Academic Word List, built specifically for language learners rather than derived from general web text. A word outside your chosen level gets its approximate rank shown, so you can see how far outside it actually is. A word we've never seen at all is flagged as informational only, with no invented replacement — some ideas genuinely need a specific word.
Idioms and phrasal verbs
Idioms rely on shared cultural context that a literal reading can't recover — "touch base" has nothing to do with baseball once you're translating it word by word. Phrasal verbs are the quieter version of the same problem: "set up" is invisible to a native reader but genuinely opaque to someone assembling its meaning from "set" and "up" separately, which is exactly why this tool suggests "configure" instead — not because it's simpler, but because it's transparent.
Long noun stacks
"Customer account management policy update" strings five nouns together with nothing to signal how they relate. This is the weakest check on the page, since it approximates "is this a noun" without a part-of-speech tagger — it's tuned to stay quiet on proper nouns and product names ("Amazon Web Services"), and the allowlist below covers anything it still gets wrong.
Why the allowlist matters
The framing here is "here's what a non-native reader may struggle with," not "your writing is bad." Technical vocabulary is often necessary, and a tool that flagged every product name, API, or domain term in a technical document would be too noisy to trust. Add your own terms to the allowlist and every rule on this page — rare words, idioms, and noun stacks alike — will stop flagging them.