QKeyboard vs Grammarly Keyboard: Which iPhone AI Writing Tool Fits You

Grammarly Keyboard and QKeyboard both install as a custom iOS keyboard and both need Full Access to send your text to an AI provider for analysis. Past that, they are built around different jobs: Grammarly is a grammar and tone checker first, and a rewriter second. QKeyboard is a rewriter first, built around switching tone with a tap and keeping a library of your own writing styles.

What Grammarly Keyboard does well

Grammarly's core strength is correctness checking. It underlines spelling and grammar issues as you type, flags tone (does this sound confident, or does it read as harsh), and offers a small set of suggested fixes inline. For people who mainly want a safety net against typos and awkward grammar across every app, that real-time underlining is genuinely useful and is the feature Grammarly is best known for.

Grammarly also has a longer track record in schools and workplaces, and its desktop and browser extensions cover more ground than a keyboard alone — useful if you write long documents outside of messaging apps.

What QKeyboard does well

QKeyboard is not primarily a proofreader. It is built around rewriting a message into a specific tone with one tap, using presets like Professional, Concise, Urgent, Direct, and Friendly. You can also build your own custom modes for writing patterns you repeat often, such as client updates or standup notes.

QKeyboard also supports bringing your own API key from OpenAI, Claude, or Gemini-compatible providers, stored in your device's Keychain. That matters if you want to choose which model handles your text rather than relying on a single fixed engine.

Side-by-side comparison

When to pick Grammarly Keyboard

If your main problem is typos, grammar slips, and wanting a second opinion on whether a message sounds off, Grammarly's real-time underlining and tone detection are built exactly for that. It is also a reasonable choice if you already use Grammarly on desktop and want the same account and dictionary on your phone.

When to pick QKeyboard

If your grammar is generally fine but you want to reshape a draft into a specific tone — softer for a client, shorter for a busy manager, more direct for a quick decision — QKeyboard's one-tap presets are the more direct path. It is also the better fit if you want a saved library of your own custom instructions, or if you want control over which AI model processes your text through BYOK. See our full breakdown of QKeyboard vs Apple Writing Tools for how QKeyboard compares to the option built into iOS itself.

Neither tool requires you to give up the other — you can only run one custom keyboard's Full Access flow at a time in most workflows, so the practical choice usually comes down to which job you do more often: checking, or rewriting.