Spell checkers and grammar tools for dyslexia — which ones actually help?
Most spell checkers were designed to catch typos — fingers that slipped on a keyboard. That's a different problem from what dyslexic writers face. When you swap a letter pair ("thier" for "their"), omit a silent letter entirely ("nite" for "night"), or phonetically spell a word whose spelling is illogical to you ("fone" for "phone"), a standard spellcheck often fails to recognise what you were trying to write. It marks the word wrong without offering the right suggestion — or worse, it silently "corrects" it to the wrong word altogether.
The tools discussed here range from the spellchecker already on your computer to specialised dyslexia-aware software. They solve different problems, and the gaps between them matter. This is an honest assessment of each, focused on the errors dyslexic writers actually make.
Why standard spellcheckers fall short for dyslexic writers
A standard spellchecker works by comparing what you typed against a dictionary and calculating edit distance — essentially, how many single-character insertions, deletions, or substitutions separate your spelling from the closest known word. That works well for transposition errors ("teh" → "the") but poorly for phonetic spellings that are several characters away from the correct form.
"Nessisary" won't surface "necessary" on many checkers because the phonetic overlap, while obvious to a human, doesn't score well on character-level distance metrics. The checker may offer "necessary" third or fourth in the list, below "necessitate" or "messianic". If you can't read the suggestion list fluently — which is itself a reading task — you may pick the wrong one.
There's a second, subtler failure mode: real-word errors. Dyslexic writers frequently swap homophones ("their/there/they're", "affect/effect", "its/it's") or produce words that are spelled correctly but are the wrong word entirely ("from" instead of "form", "on" instead of "no"). A basic spellchecker ignores these entirely — both words exist in the dictionary. Catching them requires grammar-level analysis, which only more sophisticated tools attempt.
Browser built-in spellcheck
Chrome, Firefox, Edge, and Safari all offer built-in spellcheck in text fields. It's always on, always free, and requires no setup. For many dyslexic writers this is the minimum floor — better than nothing, good for catching obvious transpositions in quick emails or form fields.
The limitations are significant, though. Browser spellcheck is dictionary-only: no grammar, no context, no phonetic matching. It also stops at the edge of the text box — it won't check what you've written in a rich-text editor like Google Docs or Notion, because those apps render their own text layers. And the red underline itself can be an obstacle: some readers with contrast sensitivity difficulties find the wavy red line visually distracting enough to break their train of thought.
Chrome's spellcheck has one useful setting: right-click a flagged word and you can "Add to dictionary", which helps for proper nouns or technical terms you use regularly. If your name is flagged every time you type it, adding it once stops the distraction permanently.
Microsoft Word and Google Docs — the defaults most people use
Word's spellchecker is substantially more capable than browser-level checking. It does offer some phonetic matching, which means "nessisary" and "accomodate" are more likely to surface the correct word at the top of the suggestion list. It also has a grammar layer that catches some homophone errors and word-choice confusion.
The Editor feature (the AI-enhanced version in Microsoft 365) goes further: it flags homophones, passive voice, wordiness, and a range of grammar issues. For dyslexic writers who produce real-word errors, the homophone detection alone is worth having. The caveat is that it's only available inside Word or the Edge browser — it doesn't follow you across the web.
Google Docs spellcheck is weaker on phonetic matching than Word, but it does flag some homophones ("there/their") and integrates with the Android and iOS spell-correction engines on mobile. The "Smart compose" autocomplete in Gmail and Docs reduces the writing burden significantly — if the correct spelling is suggested as you type, you never have to produce it yourself. Many dyslexic writers find this genuinely useful for common words they reliably misspell.
For more on making Google Docs readable, not just writable, see our guide on setting up a dyslexia-friendly Google Docs environment.
Grammarly — broad coverage with real-word limits
Grammarly is the most widely used writing assistant and works across most web apps as a browser extension, making it more useful than Word's Editor for everyday web writing. Its grammar layer is strong: it catches many homophone errors, subject-verb agreement problems, and word-choice confusion that pure spellcheckers miss.
For dyslexic writers, the key advantages are coverage and real-time feedback. Grammarly works in Gmail, Slack, LinkedIn, and hundreds of other sites. Errors are flagged as you type, with a single suggested correction that you accept with one click — you don't have to read a dropdown list. The card-style explanations are written in plain language, which helps if you want to understand the rule rather than just accept the fix.
The weaknesses matter, though. Grammarly's phonetic matching for severely misspelled words is not significantly better than Word — if your spelling attempt is far from the target, it may mark it wrong without finding the right word. It also flags stylistic issues (passive voice, sentence length) that may be irrelevant distractions if your goal is simply to catch errors before sending an email. The free tier is useful; the paid tier adds more suggestion categories but the core error-catching relevant to dyslexic writers is mostly available for free.
LanguageTool — the open-source alternative
LanguageTool is a free, open-source grammar and spell checker with a browser extension, a desktop app, and a web editor. It's a serious Grammarly alternative with particularly strong support for languages other than English — if you write in multiple languages, LanguageTool handles this more gracefully than Grammarly.
For dyslexic writers, LanguageTool's main advantage is privacy: the self-hosted or browser-only mode doesn't send your text to a third-party server, which matters in professional contexts. Its homophone detection is solid for English, and it handles some phonetically plausible misspellings better than basic spellcheckers.
The free version has a daily character limit for cloud checking. For most writers this isn't a problem, but if you're producing long documents it can become one. The browser extension is less polished than Grammarly's but is entirely functional for everyday use.
If you're writing across different sites in Chrome, pairing LanguageTool with LexiFont lets you handle both ends of the reading challenge — LanguageTool catches errors when writing, LexiFont improves readability when reading what others have written.
Ghotit — purpose-built for dyslexic writers
Ghotit is the tool most directly designed for the spelling patterns dyslexic writers produce. Its phonetic engine was built specifically to recognise the kinds of misspellings — omitted silent letters, reversed letter pairs, phonetic substitutions — that standard checkers miss. "Sience" → "science", "rythm" → "rhythm", "seperate" → "separate": these are exactly the cases Ghotit is optimised for.
Ghotit offers a desktop app (Windows and Mac), an iOS/Android app, and a Chrome extension. The Chrome extension is the most relevant for web writing. The suggestion mechanism is designed to be usable by someone who finds suggestion lists hard to read: suggestions are spoken aloud when you hover over them, so you can confirm the correct word by ear rather than by eye.
The cost is the main barrier. Ghotit is not free — a personal licence is a one-time purchase but at a higher price point than Grammarly's annual subscription. For users whose primary challenge is phonetic misspelling that Grammarly consistently fails to catch, it can be worth the investment. For users whose errors are more grammar- and homophone-based, Grammarly or LanguageTool will serve them adequately at lower cost.
Students in the UK may be able to access Ghotit through their institution's disability support arrangements — it's worth asking specifically, as it's listed on RNIB's assistive technology recommendations.
Co:Writer — prediction-first rather than correction-first
Co:Writer takes a different approach. Rather than correcting what you've typed, it predicts what you're about to write — offering word completions as you begin each word. If you can type the first two or three letters and select from a spoken, highlighted list, you never have to produce the full spelling yourself.
This prediction-first model suits writers for whom spellcheck correction is still too slow — finding your misspelled word in a correction list is itself a reading task. Co:Writer is primarily aimed at educational contexts and is used widely in schools, but the Chrome extension works on any webpage. Adults who found it useful in school sometimes continue using it.
The limitation is that prediction requires knowing approximately how the word starts. For writers who also struggle with initial phoneme mapping, the predictions can miss entirely. In that case, text-to-speech feedback — dictating and then listening to what the app transcribed — may be a more reliable strategy than any spellchecker.
A comparison at a glance
| Tool | Phonetic misspellings | Homophones / real-word errors | Works across the web | Cost |
|---|---|---|---|---|
| Browser built-in | Weak | None | Partial (not rich editors) | Free |
| Word / Google Docs | Moderate | Moderate | Only inside the app | Free / subscription |
| Grammarly | Moderate | Good | Yes | Free tier / paid |
| LanguageTool | Moderate | Good | Yes | Free tier / paid |
| Ghotit | Excellent | Good | Yes (Chrome extension) | Paid (one-time) |
| Co:Writer | Prediction-based | Good | Yes (Chrome extension) | Subscription |
The real-word error gap — why it matters most
Of all the failure modes, real-word errors are the most consequential in professional writing. Swapping "affect" for "effect" in a work email, or writing "form" instead of "from", changes the meaning of a sentence. No amount of careful proofreading catches these errors easily — because the word looks correct on the page, and dyslexic readers often find proofreading their own work harder than writing it in the first place.
The most practical defence is layered checking: write in an environment with grammar-level checking (Grammarly or LanguageTool active), then paste your text into a second tool before sending. Reading your text aloud — using the browser's built-in read-aloud or a text-to-speech extension in Chrome — catches real-word errors that no visual checker will find, because your ear hears "I sent the form this morning" and immediately notices if it says "I sent the from this morning".
The most reliable proofreading workflow: write with Grammarly or LanguageTool active, then read the finished text aloud with a TTS tool before sending. The visual check and the audio check catch different classes of error. Neither alone is sufficient.
Where Chrome reading tools fit in
These tools all address the writing side of dyslexia. Reading — the incoming text you need to process from emails, documents, and websites — is a separate challenge. If you're using Grammarly to write better emails but still struggling to read the responses, a font-switching tool completes the picture.
LexiFont is a Chrome extension that applies a dyslexia-friendly font — OpenDyslexic, Lexend, Atkinson Hyperlegible, or Comic Neue — to every website you visit. It pairs naturally with any writing tool: Grammarly handles the output side, LexiFont handles the input side. The Pro tier adds per-site font memory, custom spacing controls, and a reading ruler — worth considering if you spend a significant portion of your day reading in a browser.
The combination of a grammar tool and a reading font tool means you're covering both directions of the written communication loop — which, for most knowledge workers with dyslexia, is where the most friction lives.
Practical recommendations by profile
If your primary issue is homophones and real-word errors — words that are spelled correctly but wrong — start with Grammarly (free tier) or LanguageTool. Both catch these reliably. Pair with a TTS read-aloud check before sending important documents.
If your primary issue is phonetic misspelling — you know what you want to say but can't produce the correct spelling from first principles — Ghotit's phonetic engine is the most targeted solution. It costs more but solves a problem the other tools don't fully address.
If you're a student or work in an organisation that provides assistive technology budgets, Co:Writer and Ghotit are worth requesting specifically — both appear on most AT recommendation lists used by disability support offices.
If cost is the binding constraint, the free tier of LanguageTool plus Chrome's built-in spellcheck plus a TTS read-aloud habit covers the major error classes at zero cost. It's more manual than the paid options but effective if you're disciplined about the read-aloud step.
A note on autocorrect
On mobile, autocorrect is your most immediate spell-checking layer — and for dyslexic writers it's often the most useful one, because it corrects as you type rather than after. The challenge is that autocorrect learns from your corrections over time. If you've repeatedly overridden it to accept a misspelling, it stops suggesting the correct word. Resetting your keyboard's learned words dictionary (available in iOS Settings and Android Gboard settings) occasionally is worth doing if autocorrect has learned your mistakes rather than your intentions.
On desktop Chrome, the Enhanced Spellcheck option (Settings → Privacy and Security → Enhanced spell check) sends your typed text to Google's servers for more accurate suggestions — essentially giving you a smarter dictionary in any Chrome text field. It is opt-in for privacy reasons, but if you're already using Gmail and Google Docs it's a reasonable trade for better correction. For a deeper look at reading tools beyond spellcheck, see our guide on making Gmail readable and writable with dyslexia.