Subject line is the first thing your subscribers see in their inbox, which determines whether they will open your email or not. Focusing on your email subject lines will help you gain more customers to open your emails, avoid emails going to spam folders, and get your messages seen.

This article will show you how to write effective subject lines and how to check your subject line performance.

The subject line is the first field you'll need to fill out in the Settings of your email campaigns. Continue reading to learn how to come up with effective subject lines.

For automations, you'll be able to customize the subject line for each email block as part of a workflow. You need to click on the selected email block and then edit the Subject line on the right-hand sidebar.

Email subject lines should be short, simple, and easy to read. If you use long, complicated words, people won't read your subject line. At best, their eyes will gloss over complex words; at worst - your customers will mark your emails as spam. It is essential to make the subject line interesting and relevant. This will get more people to open your emails and make you look better as a sender.

Use simple words in your subject line, but only a few. Ideally, there should be at most 5-7 words in a sentence. It's essential for your customers to be able to quickly scan through their inbox and focus on subject lines that caught their attention. Writing a short subject line with only one or two words can sometimes be better. This makes it much more likely for your customers to read the subject line. If the subject line is good, they will actually open and read the email.

Here are some examples of great short subject lines:

Another way to get more people to open your emails is to use personalization in the subject lines. The simplest way is to add a person's name in the subject line, but don't limit yourself to this. Instead, use a powerful personalization tool that Omnisend offers, start by using the customer's name and continue up to location-based offers.

Personalization has proven to make people more likely to open emails. It may be even better when combined with automations like birthday deals and after-sale follow-up emails.

A great email marketing strategy is to use the information you already know about your customers, for example, order history, which you can check by creating segments from your Audience in Omnisend. It's easier to write personalized subject lines if you segment your customers and write emails specific to them.

To add personalization to your Subject line, click on the tag sign and choose what information needs to be inserted from the dropdown menu.

Read more about personalization in Omnisend here.

Here are some examples of personalized subject lines:

Our brains are naturally drawn to numbers, so including numbers in your subject line makes your subject line naturally intriguing. Numbers and lists are easier for our brains to process, creating curiosity and promising a quick and easy read.

Numbers and list email subject lines stand out for the same reasons that punctuation does - they are more visually appealing. It's also better to use numerals instead of spelling numbers under 10 out, as it makes the number more obvious and saves characters used.

Here are some examples of using numbers and lists in subject lines:

The use of question marks and exclamation marks can help you emphasize your subject line.

An exclamation mark instantly adds friendliness and excitement to a sentence. For example, the subject lines "Get your free discount code!" or "Get your next purchase for half price!" sound more exciting than a simple period.

A question, on the other hand, can make people more engaged. Subject lines phrased as questions prove to perform better than similar subject lines that were phrased as statements. When using questions in subject lines, try to ask a specific and relevant question and then provide a straightforward answer in the email body.

It is also best to use no more than two or three punctuation marks in each subject line. Your email can look like spam if you use too many punctuation marks. This is especially true if you use a lot of special characters. Special characters are known to trigger SPAM filters occasionally, so you need to be mindful when using them.

Simple language, a question, and proper punctuation get people to open the email and read it. Punctuation is a huge part of a healthy email marketing strategy, so don't be afraid to mix up the punctuation you use in your subject lines.

Here are some examples of using punctuation in subject lines:

Some people respond best to straightforward directions. If your email has a direct call to action, such as urging recipients to purchase your product, don't hesitate to make that clear in the subject line. It's good to make it clear to readers their next step. Otherwise, their eyes will just skim over your subject line, and they won't know they need to do something.

A good strategy is to communicate a sense of urgency and timeliness. The less time that recipients have to act, the more likely they will do so.

Here are some examples of creating urgency and using CTA:

Specific subject lines can really throw people off, but they can also cause your emails to be flagged as spam, which in the long run can hurt your sender's reputation and make your emails go directly to the spam folder. Below you can find some tips on what to avoid, not to make your subject lines spammy.

To help you come up with your perfect subject line, we have created a subject line tester that verifies if your subject line matches our best practices.

Once you type in your subject line in the field, our tester will show you a detailed analysis with tips on improving length, wording, and scannability and will show you an inbox preview.

A/B testing of subject lines compares how version A of subject line performs compared to version B of subject line within an audience, like a segment.

To start setting up your A/B Subject line (also, you can A/B test the sender's name and content along with the subject line), click on New Campaign under the Campaigns tab, locate the Email A/B test and click Create A/B test.

Once you create it, you'll be brought to the setup wizard. There you will be able to change all settings for your A/B campaign. Read a detailed guide about A/B testing content here.

If you want to learn more about subject lines and different strategies, we suggest looking at our blog posts: