Em Dash Filter

Find em dashes in a document, review smart punctuation fixes, and download a cleaned copy. Runs entirely on your computer.

A tool to help "un-AI" your AI texts. LLM-written prose has a tell: em dashes, lots of them. Em Dash Filter finds every em dash in a document, suggests a natural replacement for each one, and produces a cleaned copy that reads just as well, without the dashes. HOW IT WORKS 1. Click the toolbar icon and drop in a file (.docx, .txt, or .md). 2. Every em dash appears as a card: its location, the surrounding sentence, and a suggested replacement with the reasoning behind it. 3. Accept the suggestions, override any of them (keep / comma / colon / period / custom text...), or keep everything. 4. Download the cleaned copy. Your original file is never modified. SMART SUGGESTIONS, NO AI CLOUD The suggestion engine is a set of grammatical rules that runs entirely on your computer: • Paired dashes (an aside) → commas, or parentheses if the aside contains commas • Dash before "but", "which", "and"... → comma • Dash introducing a list → colon • Short afterthought → comma • Dash joining two full sentences → period, capitalized automatically • Number ranges → plain hyphen • Attribution dashes ("— Oscar Wilde") → kept PRIVATE BY DESIGN • No permissions requested. No data collected. No network requests. • Files are processed in the browser tab and never leave your computer. • Word (.docx) files are read and rebuilt locally. Also catches en dashes, minus signs, and double hyphens if you want the whole dash family. Open source (MIT): https://github.com/WintermuteEntertainment/emdash-filter A command-line version is included in the repo for terminal users.