★★★★★ Trusted by 10,000+ engineers & writers

Optimize AI Prompts in Real-Time.

Like Grammarly but for AI. Dynamically rewrite, structure, and expand your prompts directly inside ChatGPT, Claude, and Gemini for perfect outputs, every time.

See Promptly In Action

Type a draft prompt below or select a template preset to see how Promptly analyzes, upgrades, and compares your prompts in real-time.

Promptly Sandbox Editor
Select a template preset
✏️ Edit draft prompt
REFINING PROMPT...

Trusted By Engineers, Loved By Creators

See how Promptly users are cutting down API costs and making prompt engineering 10x more efficient.

★★★★★

"Promptly has made my development workflow 10x more efficient. I used to waste countless API key credits and hours copy-pasting prompts back and forth to refine instructions. The real-time word diff shows me exactly what's changing instantly. It saved me a mountain of time!"

MR
Marcus R. Chen
Staff Software Engineer, Stripe
★★★★★

"We were spending thousands of dollars troubleshooting prompt deviations across our writing team. With Promptly's custom context variables, we inject standard guidelines dynamically. It saves **tons of money and time** on re-runs. No more generic outputs."

SJ
Sarah Jenkins
Creative Director, Webflow
★★★★★

"The ability to bring my own Gemini API key is incredible. Promptly integrates so cleanly into my ChatGPT interface that it feels like a native feature. The visual feedback makes tweaking complex parameters satisfying and extremely fast."

DM
David K. Miller
Independent SaaS Creator

Engineered For High-Performance Prompting

Unlock the full potential of large language models with native client-side toolsets.

Real-time Optimization

Promptly monitors your text fields as you compose. Click the floating sparkle action button to automatically augment structure, instructions, and target rules.

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Word-Level Visual Diffs

Never guess what changed. Our diff overlay highlights deleted words in red background/strikethrough and inserted improvements in neon green.

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Bring Your Own Key

Save money on premium subscriptions. Tap into the built-in free daily tier, or hook up your own Google Gemini API key to run unlimited prompt refinements locally.

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Custom Variable Expansion

Define custom tags (e.g. [brand_voice], [formatting_rules]) in your local settings dashboard. Promptly automatically expands them inline before execution.

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100% Privacy Friendly

All prompt processing and variables are stored locally on your device storage. We never store or trace your text input logs.

Zero-Lag Integration

Instantly boots inside ChatGPT, Claude, and Gemini. Features lightweight content scripts that don't bloat your active browser memory.

Upgrade Your Prompts Today

Stop wasting API credits and drafting weak instructions. Join thousands of prompt engineers who use Promptly to write professional, highly efficient AI inputs in seconds.

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