Govarova Outreach
Run multi-step cold email cadences with AI personalisation, tracking, and a built-in CRM.
Cold Email & Outreach · Free forever
Free Newsletter Subject Line Tester & Scorer
Improve Open Rates With Data-Driven Subject Lines
Test open rate potential, character length, spam words, and emotional impact. Get AI suggestions to improve your newsletter open rates instantly.
Run the tool
Everything happens in your browser. Nothing you paste is uploaded or stored.
Under the hood
How this tool works
No black box. This is the exact logic the tool runs on every input you give it.
Formula
Score = 100 − SpamPenalty − LengthPenalty − CapsPenalty + PowerWordBonus
- 1
Split your input into individual items and normalise whitespace and casing.
- 2
Run each item through the signal checks that make up the formula above.
- 3
Apply the weight of every failed signal as a penalty against a perfect score.
- 4
Return a 0–100 score with the exact reasons behind each deduction.
Need this at scale?
Two Govarova products that do this automatically
The free tool handles one input at a time. These handle millions — verified, enriched, and ready to send.
Email Verification API
Validate every address in real time and block disposable, invalid, and trap emails at signup.
More free cold email & outreach tools
Register & start — free
Run Free Newsletter Subject Line Tester as often as you like. When you are ready to do it across your whole market, Govarova is waiting.