A Cold Email Copywriting Tool.

Designed to help you find Message-Market Fit?Finding the outreach message that consistently engages your ideal buyers.

Powered by data from 2M+ outbound emails every month.

stacksplit · agent Live
Step 01 · Your briefTell the agent who to write to
You
VoiceConsultative & soft
SegmentVP Marketing · Enterprise
ClusterTech Stack ROI · 6 templates
Run agent
Step 02 · Template libraryPulling proven templates
0templates scanned · 12 clusters
TPL-014 · Pattern Break TPL-041 · Tech Stack ROI TPL-027 · Founder Note TPL-058 · Stack Signal TPL-072 · Soft Pitch TPL-089 · ROI Angle TPL-103 · Event Follow-up TPL-126 · Enterprise TPL-141 · Q1 Planning TPL-167 · Timing Hook
Matched 6 templates in the “Tech Stack ROI” cluster
Step 03 · EnrichmentReading the company
nike.com
Stack signalSalesforce · Sprinklr · Google Analytics
Segment fitEnterprise · global campaigns
Live painChannel-by-channel ROI is fragmented
Timing hookPlanning for the Paris Olympics
Step 04 · ComposeCrafting the message
Voice + Segment + Enrichment + Templates
Generating 25 variations — keeping the strongest
Step 05 · OutputReady to send
SubjectUnifying Nike campaign ROI across channels

Hi John,

I noticed Nike's marketing stack pulls from Salesforce, Sprinklr, and Google Analytics.

If there were a way to add another layer that acted as the glue — letting you instantly pull channel-by-channel ROI on campaigns like Air Max Day — would that be useful?

I know now's probably not the best time, given you're likely deep in planning for the Paris Olympics, so no call needed.

Ready to send · 62 words Open in StackSplit
The Problem

Most cold emails fail for two reasons:

01

People don't test enough truly different messages.

02

And the messages they do test are usually bland and indistinguishable from everyone else's.

Think about it… how many times have you received a cold email that's genuinely made you stop, think, and reply?

The Solution

A tool to help you continuously discover and evolve winning cold email messaging.

To write not just better emails — but continuously generate new ones as old strategies fatigue.

How it works
01Enter your company.
02We analyse your product, positioning, ICP, pains, and market.
03Generate large volumes of truly unique cold emails with AI, using proven templates built from millions of real outbound emails.
04Turn messages into campaigns and send at scale through your sequencer.
05Rapidly test new angles, narratives, hooks, and offers to find true message-market fit.
Why It's Different
Most copywriting tools

Help you polish a single email.

VS
StackSplit

Is built to generate and test a huge range of genuinely different messaging — pattern-disruptive, creative, human-sounding outreach designed to actually stand out in crowded inboxes.

Finding message-market fit is about continuously testing new ideas until you find what truly resonates — not about writing one "perfect" email.

What You Get
Real emails, ready to send

No placeholders. No fluff. Just clean, simple emails.

Multiple angles in seconds

Stop relying on one idea. Test many.

Built for outbound

Everything is designed for cold email, not generic writing.

Works with your stack

Plug straight into tools like Clay and Smartlead.

Who It's For
B2B Sales Reps
Founder-led Sales
GTM Freelancers
Outbound Agencies
If you send cold emails,this is for you.
Features
01 / Template Library

A library of battle-tested outbound templates — flick through and start sending.

100+
Templates
12
Clusters
Weekly
New drops

Built from real, sent-at-scale campaigns. Pick, remix, or write your own — every template plugs straight into your workflow.

TPL-014 Pattern Break
Wrong person? Happy to redirect.

Hey {first} - quick question and feel free to ignore if I've got the wrong end of the stick. Are you the one looking after outbound at {company}?

Founder-led outbound 78w
TPL-027 Founder Note
Built this after 3 painful quarters

{first} - I'm the founder. Built this thing because I was sick of paying $40k/yr for tools that didn't move the needle. Worth a look?

Founder-led outbound 62w
TPL-041 Competitor Displacement
Saw you're using Outreach.io - fair warning

Most teams switching off Outreach this year cite the same three reasons. Curious if any of these match what you're hitting at {company}?

Competitor displacement 91w
TPL-058 Free Trial
Free for 14 days, no card needed

Quick one - built a tool that cuts campaign setup from 3 days to 30 minutes. Want me to spin up a workspace for {company} so you can poke around?

Free trial offers 54w
TPL-072 Soft Pitch
Not pitching, just curious

Saw {company} just hired 4 SDRs in 60 days - congrats on the ramp. How are you handling list-building and account research at that pace?

Mid-market outbound 69w
TPL-089 Direct Pitch
3 minutes to show you the demo

Straight to it: we help {industry} teams book 2-3x more meetings per SDR without adding tools or headcount. 3 minutes Tuesday or Thursday?

Mid-market outbound 48w
TPL-103 Event Follow-up
Was great chatting at SaaStr last week

{first} - followed up like I said. The thing we were talking about (the AI-account-research bit) - happy to do a 15-min walkthrough whenever suits.

Event follow-up 72w
TPL-118 Pattern Break
Bad time? Just say the word.

Look, no clever subject line. {company} popped up as a fit for what we do. Worth 5 mins or should I move on? Genuinely either's fine.

Founder-led outbound 44w
TPL-126 Competitor Displacement
Why 30+ teams left {competitor} this quarter

Pulled together the top reasons from churn calls. Two stood out - happy to share both even if you stay where you are. Useful context?

Competitor displacement 83w
TPL-141 Enterprise
For your Q1 GTM planning

{first} - most {industry} teams of {size} are budgeting for outbound tooling this quarter. Worth comparing notes on what's actually working in 2026?

Enterprise outreach 79w
TPL-156 Soft Pitch
Saw your post on outbound - agreed

Your take on personalisation-at-scale being broken - completely with you. We've been building toward exactly that. Worth a chat to compare notes?

Founder-led outbound 56w
TPL-167 Free Trial
Try it free - pre-loaded with your data

Already pulled {company}'s positioning, pains, and ICP into a workspace. 5-min demo, then it's yours for 14 days, free.

Free trial offers 52w
TPL-182 Event Follow-up
Promised I'd send the breakdown

Said I'd ping over the framework we were chatting about. Here's the short version - full case study at the end if you want the deep dive.

Event follow-up 68w
+87 more
In the library →
1 / 14 Drag, swipe, or use arrow keys
02 / Workspace
Workspace Intelligence

We analyse your business, product, positioning, ICP, pains, and market to build a deep understanding of what you sell and who you sell to.

03 / Segments
Segments

Create segments by defining your ICP, offer, pain points, industry, and positioning. Select a segment before generating emails so messaging stays tailored to the buyer.

04 / Clusters
Template Clusters

Group templates into strategic clusters for specific use cases.

Examples
Free trial offers
Enterprise outreach
Competitor displacement
Founder-led outbound
Event follow-up campaigns

Run entire messaging strategies against your offer in seconds.

05 / Generate
Email Generation

Generate large volumes of genuinely different cold emails using your selected voice, segment, and templates.

06 / Refinement
AI Refinement Tools

Use AI to instantly refine, expand, shorten, or rework messaging variations.

07 / Tools
Message Tools

Turn emails into fully operational outbound assets:

Generate subject lines
Create follow-ups
Build spintax
Generate Clay prompts for scale
Prepare campaigns for sequencers like Smartlead and Clay.
Pricing

Start free. Upgrade when you're ready.

Free trial
Free

No credit card required.

The StackSplit agent
Access to Voices
Start for free
Pro
MOST POPULAR
$19/ month

Everything in Free, plus:

Unlimited email generation
Access to Segments
Templates
Advanced email generation
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