Free Cold Email Tools
Built by People Who Send at Scale
Write, check, authenticate, size and forecast your cold outreach. Every tool is free, most run entirely in your browser, and none ask for your email.
Write & optimize
Draft, score and sharpen cold emails, subject lines and follow-ups — with AI when you want it, in your browser when you don't.
AI Cold Email Generator
Describe your offer and audience, get a ready-to-send 3-step cold email sequence with subjects and timing.
AI Email Subject Line Generator
Get 5 to 12 cold email subject lines with the style, character count and spam check for each one.
AI Follow-Up Email Generator
Paste the cold email that got no reply, get a follow-up with a fresh angle, send timing and two alternatives.
Email Subject Line Tester
Score any cold email subject line 0 to 100, preview it in a mobile and desktop inbox, and improve it with AI.
Cold Email Grader
Paste a cold email and get an A to F grade, a first-screen preview and a specific fix for every weak spot.
Spintax Generator & Preview
Validate spintax, count every unique variant, preview rendered emails, or let AI spin plain text for you.
AI Ideal Customer Profile (ICP) Generator
Describe your product, get firmographics, three buyer personas, buying triggers and disqualifiers.
Deliverability & compliance
Catch spam triggers, generate SPF / DKIM / DMARC records and check your copy against CAN-SPAM and GDPR before you hit send.
Email Spam Words Checker
Paste your cold email, get a 0–100 spam score with every trigger word highlighted and a fix list.
Cold Email Compliance Checker
Check a cold email against CAN-SPAM, GDPR, CASL and the Spam Act, then copy a compliant footer.
SPF Record Generator
Build a valid SPF record for your sending domain, count DNS lookups, and compare it with what is live.
DMARC Record Generator
Generate a DMARC TXT record with every tag explained, check your live record, and follow a safe rollout plan.
DKIM Record Generator
Generate a 2048-bit DKIM key pair in your browser, get the DNS record, and check any live selector.
Infrastructure & planning
Size your domains and inboxes, plan a safe warmup ramp, generate secondary domains and build email permutations.
Cold Email Infrastructure Calculator
Work out how many inboxes and domains you need for your sending target, and what they cost per month.
Email Warmup Schedule Calculator
Build a day-by-day warmup schedule for new inboxes and see the date you can start full-volume cold email.
Secondary Domain Generator for Cold Email
Generate up to 60 lookalike domains for cold email, check DNS in bulk, and jump straight to a registrar.
Email Permutator
Turn a name and a domain into every likely email address format, ready to verify, copy or search.
Calculators
Forecast pipeline, prove ROI and know when an A/B test is actually significant — no spreadsheet required.
Cold Email ROI Calculator
Turn volume, reply rate, close rate and cost into revenue, ROI, cost per meeting and a break-even reply rate.
Cold Email A/B Test Calculator
Check whether your subject line or copy test is statistically significant, and how many emails you still need.
Private by default
Calculators, checkers and DNS generators run in your browser. Your copy, domains and numbers never touch a server unless you press an AI button.
The same engine as the product
The AI generators use the same models and prompts that power ColdBox campaigns, tuned for short, human, spam-safe cold email.
Built from real sending data
Thresholds like 30 emails per inbox, 3-week warmup ramps and the 10-lookup SPF limit come from running deliverability for thousands of inboxes.
Free tools, no catch
What people ask before they trust a free tool with their copy and domains.
Suggest a toolYes. Every tool on this page is free with no account, no email gate and no credit card. The browser-based tools have no usage limit at all. The AI-powered generators run on our servers and have a fair daily limit per visitor so we can keep them free for everyone.
No. The tools are separate from the ColdBox app. If you want the same checks and generators applied automatically to every campaign, with warmup, deliverability monitoring and AI reply agents on top, you can start a free 7-day trial, but nothing here requires it.
Browser-based tools (calculators, checkers, DNS generators, permutator) never send your input anywhere; the analysis runs on your device. AI tools send the text you enter to ColdBox servers for that single request. We do not store it, log its contents, or use it to train models.
If you are setting up: the infrastructure calculator, then the SPF, DKIM and DMARC generators, then the warmup calculator. If you are writing: the AI cold email generator, then the spam words checker and cold email grader on the result. If you are optimizing: the A/B test calculator and subject line tester.
Please do. We add tools based on what cold email teams ask for. Send the idea through the contact page and, if it helps enough senders, we will build it and credit you if you like.
Want all of this on autopilot?
ColdBox writes, checks, warms, authenticates and monitors every campaign automatically, and AI reply agents book the meetings. Free 7-day trial, no credit card.