Subject Line Analyser

Want to boost your email open rates? It all starts with a great subject line.

This tool gives you instant feedback on your email subject line using proven best practices from Spotler and leading industry experts. Simply enter your subject line in the field below and receive:

  • A score out of 100
  • Quick, actionable feedback on what’s working (and what’s not)
  • Friendly pointers for improvement
  • Two rewritten alternatives you can A/B test
  • A professional review, just like you’d get from an in-house email expert

No fluff. No distractions. Just a focused review of your subject line.

Keep expanding your knowledge

Love at first click: Pre and Post Valentine’s campaigns that deliver real revenue
Event
13 Jan
Love at first click: Pre and Post Valentine’s campaigns that deliver real revenue

With the right pre and post Valentine’s campaigns, you can lift revenue, strengthen your data and turn one off shoppers into loyal customers. Join us to find out how!

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Blog
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Fall in love with SMS & WhatsApp marketing this Valentine’s: 5 ideas your audience will adore.

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Valentine’s Day, much like any other seasonal campaign, is an opportunity to get to know your customers better and make a good impression.

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Christmas Marketing Hub
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The most joyful time of year is now. Time to set up your Christmas campaign. We got you covered with our Christmas toolkit. Everything you need for a beautiful campaign can be found in our hub.

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The marketing mix Christmas wishlist 
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Get the most out of the biggest shopping season of the year with these top 10 tips to improve your marketing mix this Christmas!

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How Kempinski Hotels saw an 84% satisfaction rate from email with a custom welcome journey 
Case study
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How Kempinski saw an 84% satisfaction rate with a custom welcome journey. Have a look inside Kempinski Hotels' email series.

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Email marketing tricks that will reap you treats: how you can make the most of spooky season 
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Discover the origins of Halloween, the psychology behind why fear sells, and frightfully good ideas to boost email marketing this spooky season.

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WhatsApp vs Email: which channel really connects with today’s buyers?
Blog
WhatsApp vs Email: which channel really connects with today’s buyers?
Richard Wall 17-10-2025

Compare their strengths of these channels, from GDPR to engagement, and see how using both drives better buyer relationships. Read the blog!

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