Free tools for cold email senders

100% free. No sign up. No sign in. Runs in your browser.

A growing set of free tools for cold email senders. Every tool runs in your browser, requires no signup, and never sends your data anywhere except the Cloudflare public DNS endpoint when domain lookups are needed.

• Is your domain SPF, DKIM and DMARC ready? Free check. No sign up. No sign in.
  Check your sending domain's SPF, DKIM, DMARC, and blacklist status in one click. 100% free. No sign up, no sign in, runs in your browser. Required for Gmail and Yahoo bulk sender compliance.
• Look up any domain's DNS records. Free, instant, no sign up needed.
  All public DNS records for any domain in one query: A, AAAA, MX, TXT, CNAME, NS, SOA, CAA. Free. No sign up, no sign in. Instant results via Cloudflare DoH.
• Decode any SMTP bounce code in seconds. Free, no account needed.
  Paste any SMTP bounce error and decode the code, classification (hard/soft/throttle/auth), and exact fix. 100% free. No sign up, no sign in. Covers Spamhaus, SPF/DKIM/DMARC, mailbox full, throttling.
• Why did your email land in spam? Free header analyzer. No sign up.
  Paste raw email headers (from 'Show original' in Gmail or 'View source' in Outlook) and see SPF/DKIM/DMARC verdicts, sending path, Message-ID, and RFC 8058 compliance. Free. No sign up, no sign in.
• Will your subject line hit spam? Score it free. No sign up, no sign in.
  Score any cold email subject line before sending. Checks length, spam trigger words, ALL CAPS, emoji, punctuation, unresolved merge tags. 100% free. No sign up, no sign in, instant.
• See your email in Gmail, Outlook and Apple Mail before you send. Free, no sign in.
  See how your HTML email renders in Gmail, Outlook, and Apple Mail before you send. Free preview tool. No sign up, no sign in, no upload, runs entirely in your browser.
• Test your spintax before you hit send. 10 variations, free, no sign up.
  Test your {Hi|Hey|Hello} spintax syntax instantly. Generates 10 random unique variations of any pattern, nested up to 5 levels. Free. No sign up, no sign in.
• Generate the RFC 8058 unsubscribe headers Gmail and Yahoo demand. Free, no sign up.
  Generate the List-Unsubscribe and List-Unsubscribe-Post one-click headers Gmail and Yahoo require for bulk senders. Free RFC 8058 generator. No sign up, no sign in.
• Convert HTML email to RFC compliant plain text. Free, no account needed.
  Convert HTML email to RFC 2046 multipart/alternative plain text. Preserves link targets, list bullets, and paragraph breaks. Free. No sign up, no sign in, runs in your browser.
• Cold email math, solved. 5 free calculators. No sign up. No sign in.
  Five free calculators for cold email operators: daily send limit by provider, warmup duration, ROI projection, bounce rate impact on inbox placement, A/B sample size. No sign up, no sign in.