ColdOpen
Write my first lines
First 10 lines free — no signup

Cold emails that get answered
start with a real first line

Upload your lead list, get a researched, personalized opener for every prospect in minutes — not an afternoon of tab-switching per campaign.

Write my first linesWatch it work — 15 sec

Bring your own OpenAI or Anthropic key. It never leaves your browser.

15-second demo

From spreadsheet row to opener

Three sample leads, three lines a human would actually send.

Sarah Chen

Driftlane · driftlane.io

waiting…

queued

Marcus Webb

Kettleworks · kettleworks.com

waiting…

queued

Ana Petrova

Northbeam Labs · northbeamlabs.com

waiting…

queued

Three steps, then back to selling

1

Paste your leads

Upload or paste a CSV — name, company, website. Exports from Apollo, Clay, or Sales Nav work as-is.

2

Pick a voice

Direct, warm, or witty. One click per lead list, applied to every line.

3

Export and send

Download the same CSV with a first_line column, map it in your sending tool, launch the campaign.

Your key. Your leads. Your browser.

ColdOpen runs entirely in your browser and talks directly to your AI provider. Your API key and your lead lists never touch our servers — there is nothing for us to leak, sell, or train on. Check the network tab; we like it when you do.

One price. Not a subscription.

Try it on 10 real leads first — free, no signup.

Free

Kick the tires on real prospects.

$0
  • 10 personalized first lines
  • All 3 tone presets
  • CSV export
  • No account needed
Start free
Pays for itself in one reply

Unlimited

Every campaign, forever.

$19 one time
  • Unlimited first lines
  • All 3 tone presets
  • CSV export
  • 14-day money-back guarantee
  • You keep paying your AI provider pennies, not us
Use your 10 free lines first

Questions people actually ask

Where does my API key go?

Nowhere. It's saved in your browser's local storage and used to call OpenAI or Anthropic directly from your browser. Our server never receives, sees, or logs it — you can verify this in your browser's network tab: the only requests leaving the page go straight to the AI provider.

Where does my lead list go?

Same answer: it stays in your browser. We don't upload your CSV anywhere. Close the tab and it's gone.

What does it cost to run?

You pay your AI provider pennies — roughly $0.10–0.30 per 1,000 lines with a small model. ColdOpen itself is $19 once, forever. No subscription, no credits.

Do the lines actually sound human?

The prompt is tuned against the classic AI tells: no 'I love what you're doing', no invented facts, hard 25-word cap, and it must reference something real about the company. Pick direct, warm, or witty to match your sending voice.

What's your refund policy?

If the lines don't earn their keep, email us within 14 days of purchase and you get the $19 back. No forms, no questions.

Does it work with Smartlead / Instantly / lemlist?

Yes — you get back your original CSV with a first_line column added. Map it to a custom variable in any sending tool.

Your next campaign deserves a better first line

10 free lines. No signup. Two minutes from CSV to export.

Write my first lines