subject line ideas to test in your next email

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To open or not to open—that is the question.

Subject lines serve as the first impression your subscribers receive when your emails land in their inboxes. A well-crafted subject line has the potential to persuade subscribers to open your marketing emails and take that crucial step toward conversion. However, coming up with solid subject line ideas isn’t always easy. 

That’s why I've compiled 40+ subject line testing ideas for you to explore in your next campaign.

The Importance of Subject Line Testing

Think of subject line testing as a treasure hunt for engagement. By experimenting with different ideas, you can discover what really resonates with your audience. Testing isn’t just a good practice; it’s essential for maximising your email marketing effectiveness. 

Most email service providers (ESPs) make it easy to set up A/B tests—sometimes in just a few clicks. Test a percentage of your email list, see which subject line wins, and then send the champion to the rest. 

It’s like having a mini competition right in your inbox!

Subject Line Testing Ideas

Let’s break down some creative ways to test your subject lines:

Emojis vs. No Emojis

You’ve probably noticed emojis popping up in subject lines all over the place. But how do they perform compared to traditional subject lines? Testing whether emojis enhance your subject lines or distract from your message can provide valuable insights. Here are some emoji subject line examples to inspire you:

• 🎁 Pick your gifts, Brenda

• Find The Perfect Gift 💞 Mother’s Day Gift Guide

• ⚡Sunday Steal!!! ⚡

• Show your hubby he’s special 🤵❤️

• Elegant in emerald💚

• Because 🏠 is the new office

• Be inspired by animals in art 🐯 🐘 🐦

• Stuck indoors? Surf our sale section 🌊

• Can you solve this dino-mite puzzle?! 🦖🧠

• Tik Tok…Time Is Running Out! ⏰

• ⏰You snooze, you lose.

• Refresh Your Spring Beauty Routine 💐

When using emojis, ensure they fit the context and brand personality. An emoji can draw attention, but it should also align with the message you're conveying.

Short vs. Long Subject Lines

Typically, shorter subject lines (60 characters or fewer) see higher open rates than longer ones. However, this might not hold true for all brands, making it worthwhile to experiment with subject line length. Here are some examples of shorter subject lines that may engage your audience:

• Don’t forget about your birthday treat on us!

• The pieces you’ll wear on rotation

• Love the color Blue? Check out our favorites…

• How’s Your Weekend Going?

• Big splash: 50% off all swim tonight only

• Hurry, but Don’t Worry: 10% Off Ends Tomorrow

Testing both shorter and longer subject lines can help you identify what length resonates most with your audience.

Question vs. Statement Subject Lines

Questions can pique curiosity, while statements can provide clarity. Try flipping your existing statements into questions and see which performs better. Here are some question-based subject line ideas you can consider:

• Need Some Help Getting Ready For Your Next Project?

• Who doesn’t love a floral-print dress?

• Ready to take your style to new heights?

• Looking for ways to help healthcare heroes? We got one!

• Want A Special Birthday Surprise?

• Looking for everyday supplies?

• Sick Of Your Sweatpants Yet?

• Did you check out this sale yet?

• Have you heard? Select styles up to 50% off!

• Hi! Remember Us? 🖤

• Need an excuse to treat yourself? 👉👉👉

• Looking to Lounge?

By reframing existing statements into questions or vice versa, you can gain insights into how your audience prefers to engage with your content.

The results might surprise you!

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Urgency vs. Savings Subject Lines

Are your customers more motivated by the prospect of saving money or by urgency? This is a crucial test for retailers looking to refine their subject line strategies. Here are examples of savings-oriented subject lines:

• Buy This Shirt = Save $11

• Save at Home: Extra 25% off All Sale

• Member Exclusive Sale: Save up to 40%

• We want to save you some money

• NEW SHORTS! Plus, save 20% when you spend $75 💛

On the flip side, urgency-driven subject lines can look like:

• Hurry, buy now during the Fall Savings Event.

• Hurry… Your Exclusive Ends Midnight ⏳

• Hurry – Your $5 in rewards expires soon!

• your special treat ends soon…

• Ending soon: 50% off entire site!

• It’s your last chance.

• Last Chance // 40% off Sandals Ends Tonight

• 💋Don’t miss our BIGGEST deal yet!

• Don’t Miss This Spring Deal! ⌛

• Don’t miss out on these AMAZING offers ✨

• Your favorites are almost sold out

• Almost Sold Out! 🚨

• Low stock alert ✨

• Don’t miss out! 💙 Low Stock Alert

Finding out which approach works best for your audience can significantly improve your open rates and overall campaign effectiveness.

Common Subject Line Mistakes to Avoid

As you work on your subject lines, it's essential to avoid common mistakes that can hinder your email marketing efforts. Here are a few to keep in mind:

• Overly Long Subject Lines: Space is limited, so keep subject lines between 35-40 characters to avoid truncation by email providers.

• Vague Subject Lines: Make sure your subject lines pique subscribers’ interest by clearly indicating the email’s purpose. Avoid vague terms like "Hello" or "Important information."

• Excessive Punctuation: Overusing exclamation points or symbols can come off as spammy and may annoy subscribers. Stick to a conversational tone.

• Misleading Subject Lines: Avoid using misleading or inaccurate subject lines just to get opens. This tactic can damage your relationship with subscribers.

Find Better Subject Line Ideas

For even more tips on subject line testing, consider exploring various online resources that focus on effective email marketing strategies. Testing and refining your subject lines is an ongoing process that can enhance your engagement and conversion rates.