If I sold my company today, I’d start my next multi-million
dollar business in 90 days using only AI.
Here’s how.
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
The interesting part is whether the 90-day edge comes from AI or from already knowing exactly what to build.
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
UT
United Transfer
@UnitedTransfer · 8m
Another midfielder linked. Another “here we go” loading. Manchester United’s transfer window is turning into a full series.
How it lands
Playful, but skeptical
The post jokes about repetitive transfer reporting while showing real interest in what happens next.
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.
Tone detected
Optimistic
The post celebrates progress, but makes it clear that the work is not finished yet.
Overall
Positive
Nuance
Cautious
Confidence
84%
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.
Built for X and Reddit.
Generate X replies in seconds.
Choose a tone, generate three drafts, and inject your favorite directly into the X reply composer.
Generate Reddit comments with context.
Undertone uses the post title, body, author, and subreddit to generate comments that fit the discussion.
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?
You can describe your style, choose your interests, and save a few real post-and-reply examples. Undertone uses the closest examples as guidance for future drafts.
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.