If I sold my company today, I’d start my next multi-million
dollar business in 90 days using only AI.
Here’s how.
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Chrome extension
Read the room.
Reply like you.
Undertone reads the post, generates replies in the tone you choose, and learns your writing style—so you can reply faster without sounding automated.
undertone
X post
Post read
Bold, promotional
92% confidence
The post uses a confident claim to create curiosity and position AI as a shortcut to building quickly.
Natural
Analytical
Funny
Natural draft
you’d do it in 90 days because you’ve already done it once. the AI is a footnote
Generate the reply you need.
Pick X or Reddit, choose a tone, and get three drafts you can use immediately or edit first.
undertone
Post detected
DO
David Ornstein
@David_Ornstein · 12m
🚨 EXCL: Arsenal exploring move to sign Vinicius Junior from
Real Madrid. #AFC interest
early stage + clubs not yet in talks but idea approved at all
levels. Much rests on contract process as no breakthrough yet
& #RMFC do not want free
exit
@TheAthleticFC
How it lands
Breaking, but heavily hedged
The post opens with an exclusive claim and then qualifies almost every part of it, so the interest is real while the deal is nowhere near done.
Tone
Ways in
Three drafts in your selected tone
From post to reply in seconds.
Open a post, choose how you want to sound, and let Undertone prepare replies you can inject directly.
Open any post.
On an individual X or Reddit post, Undertone collects the text and relevant page context automatically.
Pick a tone.
Choose Natural, Analytical, Supportive, Creative, or Funny. Undertone generates three distinct options at that tone. You can also give it a phrase or point you want to keep.
Train it on your writing.
Save a few real post-and-reply examples. Undertone uses your phrasing, interests, and humor instead of generic AI copy.
KM
Kai Mercer
@kaimerce · 3m
Original post
AI · Music
Someone made an AI version of Drake’s “God’s Plan.”
Matched to your voice
2 similar replies
nahhh this is too much bruh, now we got Drake singing about Claude
has enough slop.
Reply like yourself.
Paste a few post and reply pairs you actually wrote. Undertone learns your phrasing, humor, and point of view.
Paste a few. Undertone learns the pattern.
Two ways to teach your voice.
Add a few examples yourself, or import your latest replies from X.
01
Add examples
Paste replies you wrote directly into the extension.
02
Import from X
Connect your account and bring your real reply history in.
Built for where conversations happen
X
Reddit
Frequently asked questions.
Does Undertone post anything automatically?
No. It creates drafts for you to review, edit, and choose. You remain responsible for what gets posted.
How does it learn my voice?
Paste post-and-reply examples in the extension, or — once accounts ship — connect X in your dashboard, export your latest replies as JSON, and import that into settings.
Does it work on every page?
Undertone works on individual X and Reddit post pages, where it can reliably read the context needed for useful replies.
Are my voice examples public?
No. Voice settings and saved examples stay in your browser and are only used when you ask Undertone to generate replies.
Get Undertone before launch.
Join the waitlist for early access, product updates, and the first Chrome release.