The plain text vs html email debate gets treated like a religious argument online, and it shouldn't be, because the honest answer is that both have real strengths and the right choice depends on what you're sending and to whom. Here's an even look at both sides.
Plain text email is just words, with no images, colours or layout. HTML email is coded like a small web page, so it can carry branding, buttons and pictures. Use plain text, or lightly designed HTML that looks plain, for personal and relationship emails, and full HTML for launches, sales and product-heavy sends.
Who this is for: newsletter senders deciding between a designed template and plain emails
Plain text email is exactly what it sounds like: unformatted text with no images, no coloured buttons, no custom fonts and no bold. Links show as full web addresses. It looks the way you would type a note in a basic text editor.
HTML email is built with the same code as a web page. That lets you control layout, add images and a logo, use brand colours and fonts, and make buttons that look like buttons rather than underlined blue text.
Two details most comparisons miss:
Here is how plain text, lightly designed HTML (the middle ground) and fully designed HTML stack up on the things that matter.
| Plain text | Lightly designed HTML | Full HTML | |
|---|---|---|---|
| Deliverability | Fewest things to go wrong | As good as plain if the code is clean | Fine if well coded; heavy images and broken code cause trouble |
| Promotions tab likelihood | Lowest | Low | Highest, because it looks like a campaign |
| Tracking | Clicks only (no open pixel) | Opens and clicks | Opens and clicks |
| Design | None | Small logo, bold, one button at most | Full layout, images, brand colours, multiple buttons |
| Accessibility | Very good for screen readers, but long raw links are hard to follow | Very good with real text and descriptive links | Good only with alt text, real text (not text in images) and enough contrast |
| Rendering | Looks the same everywhere | Looks almost the same everywhere | Needs testing across Gmail, Outlook and Apple Mail |
| Best for | Cold outreach, one-to-one replies, transactional notes | Newsletters, welcome sequences, founder emails, sales follow-up | Ecommerce, launches, product round-ups, event invitations |
A note on tracking: open rates have become less reliable for every format since Apple's Mail Privacy Protection started loading tracking pixels automatically for many readers. Clicks and replies are better measures of whether an email worked, whatever format you use.
Gmail sorts mail into tabs automatically, and it looks at the whole picture: who sent it, how people usually react to that sender, and what the message looks like. A wide banner image, a grid of products, several buttons and a big footer all look like a marketing campaign, so the email is more likely to land in Promotions. A short email that looks like a person wrote it is more likely to land in Primary.
So format matters, but it is one signal among several. Plain text will not save a sender with a poor reputation, and a clean, well-coded HTML email from a sender people open and reply to can land in Primary too. HTML is not the problem; badly built HTML is. Google's own email sender guidelines say HTML messages should follow HTML standards, and warn that using HTML and CSS to hide content can get messages marked as spam.
If your emails are going to Promotions and you want to know why, read why emails go to Promotions, and run your email through our free email deliverability checker to see what is setting it off.
Plain text, or HTML that looks like it, tends to win when the goal is a reply or a feeling of direct contact rather than a click on a designed button:
Plain text also renders the same everywhere, since there is no layout to break across mail apps or screen sizes. That removes a whole round of testing.
HTML earns its place when the picture does real work:
If you use full HTML, keep plenty of real text in the email (not text inside images), add alt text to every image, make the button text describe what happens, and test on mobile. Our guide to mobile friendly email design covers the checklist.
A lightly designed email is the middle ground most senders should use most of the time. It is HTML, so it can track opens and clicks and use a little formatting, but it is built to look like a personal email.
A simple recipe:
You keep the tracking and a touch of brand, and the email still reads like a letter. For most newsletters and nurture sequences this beats both extremes.
The most quoted figures come from HubSpot. In its article Plain Text vs. HTML Emails: Which Is Better?, Niti Shah reports a series of A/B tests on HubSpot's own lists. In one, an HTML template with images had a 21% lower clickthrough rate than the plain text version, and combined with a lower open rate it got 51% fewer clicks. HubSpot's summary was blunt: "In every single A/B test, the simpler-designed email won."
Read those figures with care. They come from one B2B software company emailing its own audience, the article does not give sample sizes for each test, and the same article notes that ecommerce senders may get very different results. HubSpot's own survey from that time also found that nearly two-thirds of respondents said they preferred HTML and image-based emails, which shows how far what people say can differ from what they click.
The honest answer is that tests vary by list, industry and offer. The only statistic that matters for you is your own. Send the same email in two formats to two random halves of your list, keep the subject line identical, and compare clicks and replies. Our guide on how to A/B test emails shows how to set it up so the result means something.
If you use Outlook you will see a third option: Rich Text Format, or RTF. It is an old Microsoft format that supports bold, colours and attachments placed inside the message. According to Microsoft's own support page, RTF only works in classic Outlook and old Exchange clients, Outlook converts it to HTML when you send to people outside your organisation, and Microsoft calls it a legacy format and recommends HTML instead.
So for HTML vs RTF the answer is simple: use HTML. HTML is already Outlook's default. If you want a plain email in Outlook, switch that message to plain text, but know that it drops bold, colours and pictures inside the message (you can still attach files). Some recipients also set their own mail app to show everything as plain text, which is another reason every HTML email should make sense without its images.
When you merge to email from Word through Outlook, you pick the mail format: HTML, plain text or attachment. HTML keeps the formatting from your Word document, such as bold, links and tables. Plain text strips all of it, which can make a merged email look more like a personal note.
For a small, personal send, such as a note to past clients or event attendees, plain text or simple HTML works well. For anything bigger, use a proper email platform instead of a mail merge from your own mailbox. Platforms handle unsubscribes, bounces and sending limits, and they protect your everyday mailbox from being flagged for bulk sending.
Neither format gets blocked for being HTML or plain text. What matters most is your sender reputation, authentication and how people react to your emails. Plain text has fewer things that can go wrong, while badly coded or image-heavy HTML can cause problems. A clean, lightly designed HTML email performs about as well as plain text.
They are more likely to, because they look like a personal email rather than a campaign. It is not guaranteed. Gmail also looks at who sent it and how people usually respond to that sender, so a plain email from a sender with poor engagement can still land in Promotions.
No. Open tracking works by loading a tiny invisible image, and true plain text cannot contain images. You can still track clicks, because links can be rewritten to pass through your email platform. If you want open tracking, use a lightly designed HTML email that looks like plain text.
For most founder, coach and consultant newsletters, use lightly designed HTML: one column, normal font, few images, links in the text. It reads like a personal letter and keeps tracking. Save full HTML design for ecommerce, launches and product round-ups where images do real work.
HTML works in every modern mail app and is Outlook's default. RTF (Rich Text Format) is an old Microsoft format that only works in classic Outlook and Exchange, and Outlook converts it to HTML when you email anyone outside your organisation. Microsoft recommends using HTML.
Whichever format you choose, it only works if it reaches Primary. If you're curious whether your current HTML template is hurting your placement, we offer a free deliverability audit to check.