Plainprose

A calm place to write, and a clear look at what makes your writing hard to read. Write in a quiet editor with nothing in your way. When you're ready, switch on Edit: Plainprose marks long and very long sentences, wordy phrases that have a plainer choice, adverbs, passive voice and filler words, and shows the reading grade of your text. Everything runs on your computer.

Try the free demo in your browser: every check, Start here, the rhythm strip and your world's names, with one document kept in your browser. Opening and saving files, versions and export are in the full version.

What makes it different

• Start here. It doesn't just highlight problems; it lists the three changes that would make your text easiest to read, with what each one does ("Split this 58-word sentence: grade 4.6 → 3.9"), and fixes plainer words and filler with one click.
• The rhythm strip. Every sentence is a bar beside the page, so you can see at a glance where the writing drags or turns choppy, and jump straight there.
• Your world's names. Add your characters and places once. They're never flagged as hard words, and near-misspellings get caught: "Kaeleth"? Did you mean "Kaelith"?

What it does

• Write, Edit and Focus modes. Write shows no marks at all. Edit shows them. Focus dims everything but the paragraph you're on and keeps your line steady as you type.
• Marks that explain themselves. Hover or click any mark for a short, plain reason and, where there is one, a plainer word to swap in.
• Reading grade in plain words ("Easy for most adults"), word count, reading time, and word goals for the document and for today.
• Your files stay yours. Plain .txt and .md files on your disk, autosave, and a version history you can restore. If the power goes, your last words are kept.
• Find and replace, three themes (dark, paper, sepia), your choice of font and line width.
• Export to .txt, .md, .html and .rtf.
• Choose which checks you see; turn on long words and repeated words when you want them.

What you get

• Windows app (64-bit, Windows 10 or 11). Unzip and run; nothing to install.
• Browser version: a single HTML file that runs offline in Chrome or Edge.
• English checks today, built so more languages can be added in updates.

Private by design

Your writing never leaves your computer. There's no account, no telemetry and no AI service; the app makes no internet connections at all.

Good to know

• The Windows app isn't code-signed, so Windows SmartScreen will warn the first time you open it: choose "More info", then "Run anyway".
• The Windows app has no spell checker yet (it would need an internet download). The browser version uses your browser's own.
• The checks are guides, not rules. A long sentence can be the right sentence.

How it was made

Plainprose was made with AI help: the code, the logo, the sample texts and this page were produced with AI tools (Claude and Codex) under human direction, then checked by automated tests and by hand. The app itself has no AI features: every check is a plain rule that runs on your computer.

Licence (summary)

• Your writing is yours. The app claims nothing in what you write.
• One licence per buyer, on any computers you use. Don't share or resell the app itself.
• No warranty. The full licence is in the download.

Questions or a bug? Leave a comment below.