AI-powered replies that understand full thread context, match your voice, and generate in under 2 seconds.




User
@user_handle
What is the best way to grow on X in 2026? I have been posting consistently but my engagement is flat. Any tips?
"Consistency is great but engagement comes from replies. Spend 30 min/day replying to accounts in your niche. Add genuine value, not just 'great post!' That's how you build real connections."
800k+
Followers Managed
20k+
Replies Sent
2.8M
Engagement Generated
4.9/5
Chrome Store Rating
XFastr is packed with features that make your X engagement faster, smarter, and authentically you.
AI reads the entire conversation thread before crafting your reply. No more out-of-context responses.
The fastest reply generation on the market. Your reply is ready before you finish reading the tweet.
Speak your thoughts and let AI transform them into polished, engaging replies. Brand new feature.
Witty, professional, casual, sarcastic — set your default tone or change it per reply.
Not happy with the first draft? Regenerate for a fresh take — each one different from the last.
Your data stays yours. We never store your tweets or train on your content.
Add XFastr to Chrome in one click. Works on all Chromium browsers — Chrome, Brave, Edge, Arc.
Install ExtensionBrowse X like you normally do. XFastr automatically generates a reply for every tweet you see — no clicking, no touching anything.
Review the reply, tweak if needed, and post. Watch your engagement and followers grow organically.
See what people are saying about XFastr.
"Bro.. It's really great. The reply feel likes human, not too AI. This a great tech for everyone who grinding on x."

Gargamel
@Lahilapagi · 2k followers
"This reply tool is excellent."

Tadeo Uzo
@TadeoUzo
"Really nice overlay and growth tool!"

ToneDice
@JosiTonedice · 4.9k followers
"Holy shit you cooked him"

Theo - t3.gg
@theo · 300k followers
Try XFastr with limited features.
Perfect for individuals growing their presence on X.
For power users and teams serious about engagement.
Our AI analyzes the entire conversation thread — every reply, quote tweet, and the original post — to understand tone, topic, and nuance before generating your reply. This means you never sound out of context.
Yes! The Voice to Reply feature is included in both our Pro and Unlimited plans. Simply tap the microphone icon, speak your thoughts, and our AI will craft a polished reply from your voice input.
We consistently generate replies in under 2 seconds. Our infrastructure is optimized for speed without sacrificing quality. You will see the reply appear almost instantly after clicking generate.
Absolutely. You can set a default tone (professional, witty, casual, etc.) and override it on a per-reply basis. The AI adapts to match your unique voice and communication style.
Regenerations are limited based on your plan — Starter gets 100/month and Pro gets 500/month. Initial reply generation is always unlimited.
No. We process tweets in real-time to generate replies but never store your tweet content or train our models on your data. Your privacy is fundamental to our product design.
XFastr is available as a Chrome extension and works on all Chromium-based browsers including Chrome, Brave, Edge, and Arc.
Join thousands of creators who are growing their audience with AI-powered replies.