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Grammarly vs KAI KeyboardAI

Two fact sheets from our own research, side by side — pricing, platforms, API access and status re-checked by us rather than quoted from the vendors. Grammarly starts at $12, KAI KeyboardAI at $4.99. Both have a free tier.

GrammarlyGrammar, tone and rewriting help inside every appKAI KeyboardAICustom iPhone keyboard that rewrites, replies and drafts with AI inside whatever app you are typing in.

Side by side

FactGrammarlyKAI KeyboardAI
CategoryGrammar & ProofreadingAI Writing Assistants
Pricing modelFreemiumFreemium
Starts at$12 month$4.99 month
Public APINoNo
PlatformsWeb, Chrome Ext, Windows, macOS, iOS, AndroidiOS
CompanySuperhumanAkshat Giri LLC
Launched20092023
Last verifiedSep 6, 2026Sep 6, 2026

What our research says

Grammarly

Still the default for catching mistakes inside other people's software, but the free tier has quietly become an AI-prompt meter and the honest price is $30 unless you commit to a full year.

Pros

  • Runs inside the apps people already write in rather than as a separate editor
  • Free tier still covers spelling, grammar and tone detection with no time limit
  • Pro folds in plagiarism and AI-text detection that rivals charge for separately

Cons

  • The $12 headline is the annual rate; paying monthly costs $30
  • Free AI allowance is 100 prompts a month and depletes quickly
  • No public API, so it cannot be embedded in another product
  • Enterprise pricing is not published anywhere on the site

KAI KeyboardAI

A keyboard is the right shape for this problem — you rewrite the message where you are typing it instead of copying into a chat app and back. KAI does that, cheaply. The problem is age: the last update was November 2023, and an AI product frozen for that long is running on whatever model it shipped with.

Pros

  • Works system-wide as an iOS keyboard, in any app
  • Free to install with a one-off All Access unlock rather than a heavy subscription
  • Ships English, Russian and Ukrainian support
  • Named developer with a live App Store listing

Cons

  • No update since version 2.1 in November 2023
  • Billing period on the $4.99 and $39.99 purchases is not stated anywhere
  • Rated 18+, which blocks it for school-age users
  • Third-party keyboards need full access, meaning what you type can leave the device

Which one fits

Choose Grammarly if you need

  • Anyone writing in a browser, Word or email who wants corrections in place
  • Teams enforcing a house style guide across people who are not writers
  • Non-native English speakers who want fluency rewrites, not just error flags

Choose KAI KeyboardAI if you need

  • Rewriting messages in place on iPhone
  • Non-native English speakers drafting on mobile
  • People who want AI writing without a separate app

More comparisons

All KAI KeyboardAI alternatives →Browse all Grammar & Proofreading →