AI Spell Checker for Mac — Catch Typos That Dictionary Checkers Miss

An AI spell checker does something a dictionary-based checker cannot: it reads context. Traditional tools flag words that aren't in their word list and ignore everything else. That means "thier" gets a red underline, but "their going to recieve it" passes without complaint — both words exist in the dictionary, just not in the right places. An AI spell checker understands the sentence and catches both kinds of errors.

WunderType brings this to every app on your Mac with a single keyboard shortcut.

Why AI Spell Checkers Catch More Errors

Dictionary-based spell checkers compare each word in isolation. If a word exists in the dictionary, it passes. This creates blind spots:

• Homophones: "their" vs. "they're" vs. "there" — all valid words, but only one is correct in context
• Its vs. it's: A missing apostrophe changes the meaning entirely, and traditional checkers won't flag it
• Real-word typos: "form" instead of "from", "causal" instead of "casual" — the misspelling happens to be another valid word
• Transposed letters: "recieve", "neccesary", "documeents" — patterns that a language model recognizes instantly

An AI spell checker processes the entire sentence at once. It knows that "thier" should be "their" and that "their going" should be "they're going" — two different corrections that require understanding grammar, not just matching a word list.

See It in Action

Here's a business email draft full of the kind of misspellings that slip past a quick proofread:

Before

Thier going to recieve the shipment on Wenesday. The pacakge contians all the neccesary documeents for the reviw. Its importent to check evrything.

Select the text in any Mac app, press ⇧⌘S, and WunderType fixes every error:

After

They are going to receive the shipment on Wednesday. The package contains all the necessary documents for the review. It is important to check everything.

Count the corrections: "Thier" to "They are" (homophone + contraction), "recieve" (transposed vowels), "Wenesday" (missing letter), "pacakge" (transposed letters), "contians" (transposed letters), "neccesary" (doubled consonant), "documeents" (doubled vowel), "reviw" (missing letter), "Its" to "It is" (homophone), "importent" (wrong vowel), "evrything" (missing letter). That's eleven errors caught in three sentences — including two homophone corrections that a dictionary checker would never flag.

Set Up an AI Spell Checker in WunderType

1. Click the WunderType icon in your menu bar and open Custom Prompts
2. Create a new prompt named "AI Spell Check" with this instruction: Fix all spelling errors, correct homophone mistakes (their/they're, its/it's, your/you're), and fix transposed or missing letters. Do not change tone, style, or sentence structure — only fix misspellings.
3. Assign ⇧⌘S as the keyboard shortcut

The key difference from a general writing polish: this instruction tells the AI to only fix spelling. It won't rewrite your sentences or change your voice. It focuses entirely on catching misspelled words, including the context-dependent ones that trip up every other spell checker.

Where It Works

WunderType runs as a macOS menu bar app and works system-wide. Mail, Slack, Notes, Pages, TextEdit, Google Docs in Safari — anywhere you can select text and press a keyboard shortcut. No browser extension needed, no per-app setup. One shortcut covers every app on your Mac.

Most AI spell checker tools are browser-based or limited to a single app. WunderType works at the operating system level, so you get the same AI-powered spelling correction everywhere you type.

Download WunderType from the Mac App Store and catch the typos your spell checker has been missing.