5 Best AI Keyboard Apps for iPhone in 2026 (Free & Paid)

Promptly takes a different approach than most AI keyboards. Instead of giving you a fixed set of features, it lets you create your own AI actions with custom instructions — and run them with a single tap, right from the keyboard.

Powered by GPT-5, Promptly works as a system keyboard in any app. You type or select text, tap an action, and the AI processes it instantly. Built-in actions include Assistant (for quick questions) and Fix (grammar correction), but the real power is in custom actions — translate to a specific language, rewrite in a specific tone, generate hashtags, summarize, or anything you can describe in a prompt.

Why it stands out

• Custom AI actions: Create unlimited one-tap actions with your own instructions. No other keyboard offers this level of customization.
• Apple Watch app: Voice AI assistant for Apple Watch with Text-to-Speech (9 premium voices), conversation history, and independent operation.
• BYOK option: Bring Your Own Key — use your own OpenAI API key for unlimited usage at cost.
• Privacy-first: No data collection, no keystroke logging, GDPR compliant.

Pricing

• Free: 30 requests/month, all actions
• Pro: €2.99/month — higher limits, Apple Watch Text-to-Speech
• BYOK: Free (use your own OpenAI API key) — unlimited usage

Best for: Users who want a flexible AI keyboard that adapts to their specific needs. Power users, multilingual typists, and anyone who wants AI beyond grammar checking.

Grammarly is the most established name in writing assistance. Its iOS keyboard provides real-time grammar, spelling, and punctuation corrections as you type. It supports proofreading in 6 languages (English, Spanish, French, German, Portuguese, Italian). The free tier includes 100 AI prompts per month. The Pro tier adds tone detection, clarity suggestions, and unlimited generative AI rewriting via GrammarlyGO.

Key features

• Grammar & spelling: Industry-leading accuracy for English text
• Tone detection: Shows how your message might sound to the reader (Pro)
• GrammarlyGO: AI-powered text rewriting and generation (Pro)
• Works in all apps: Standard keyboard extension

Best for: Writers and professionals who need reliable grammar checking, especially in English.

SwiftKey has been a popular third-party keyboard for years. Now owned by Microsoft, it includes AI-powered features like tone rewriting, text predictions, and excellent multilingual support with swipe typing. SwiftKey Premium ($1.99/mo) unlocks additional AI writing features and themes.

Key features

• Swipe typing: One of the best swipe-to-type implementations
• Multilingual: Supports 100+ languages with auto-detection
• Tone rewrite: Rewrite text in Professional, Casual, Polite, or Social Post tones
• AI predictions: Microsoft AI-powered next-word prediction
• Clipboard manager: Saves recent copies for quick access

Best for: Multilingual typists who want a free, full-featured keyboard with basic AI.

Paragraph AI is an AI writing assistant with a keyboard extension. It focuses on generating and rewriting longer-form text — emails, messages, essays. The keyboard includes templates for common writing tasks like professional emails, social media posts, and cover letters. The free tier allows 5 uses per day with a 1,000 character limit.

Key features

• Writing templates: Pre-built templates for emails, posts, letters
• Tone adjustment: Rewrite in different tones
• Grammar correction: AI-powered proofreading
• Text expansion: Expand short notes into full paragraphs

Best for: Users who write a lot of emails and want AI-powered templates for common writing tasks.

Typewise takes a unique approach with a honeycomb-style keyboard layout designed to reduce typos. Developed in partnership with ETH Zurich, it uses on-device AI for autocorrect and next-word prediction. The free tier includes AI editing tools like proofreading, tone adjustment, and translation.

Key features

• Honeycomb layout: Unique hexagonal key layout with 70% larger keys
• On-device AI: Autocorrect and predictions run locally
• AI editing: Proofread, adjust tone, translate, shorten/extend (free)
• Multilingual: 40+ languages with auto-detection

Best for: Users who make a lot of typos and want a keyboard designed to prevent them.

What About Apple Intelligence?

Apple Intelligence is not a keyboard app — it's a built-in iOS feature available on iPhone 15 Pro and newer (iOS 18+). You access it by selecting text and tapping Writing Tools in the context menu. It offers proofreading, rewriting (Friendly, Professional, Concise), and summarization. It's free, requires no installation, and works in most text fields. Since it's a system feature rather than a third-party keyboard app, we don't include it in our ranking — but it's worth knowing about if you have a compatible device.