An accessible email signature comes down to a handful of checks: text you can read against its background, alt text that says something, links that say where they go, no information locked inside a picture, and an order that makes sense when read aloud. Most of them cost nothing and take ten minutes.
We map each check to a success criterion in the W3C’s Web Content Accessibility Guidelines (WCAG) 2.2. W3C describes WCAG as a standard for web content and says it can also be applied to non-web technology such as documents, through a companion guide called WCAG2ICT. An email is not a web page, so we use the criteria as a yardstick, not as a legal test, and we read no law. We opened the W3C pages linked below and three Microsoft help pages in October 2026. We have not tested any signature with a screen reader, so treat our reading-order advice as a prediction to check.
An accessible email signature in six checks
- Contrast: 4.5 to 1 for ordinary text, including 13 pixel text (WCAG 1.4.3).
- Alt text: say what the picture is for, and leave decoration empty (1.1.1).
- Words, not pictures: no phone number or address that exists only in an image (1.4.5).
- Links: text that says where it goes, never “click here” (2.4.4).
- Colour: not the only clue that something is a link (1.4.1).
- Order and size: a sensible reading order, and targets of 24 pixels or more (1.3.2, 2.5.8).
The accessible email signature checklist, by success criterion
| Check | Criterion and level | What the W3C page says | In a signature |
|---|---|---|---|
| Text contrast | 1.4.3, AA | At least 4.5 to 1 for normal text and 3 to 1 for large text (18 point, or 14 point bold). Logos and brand names are exempt. | A 13 pixel line is normal text. |
| Text alternatives | 1.1.1, A | Non-text content needs a text alternative that serves the same purpose. Pure decoration should be implemented so assistive technology can ignore it. | Alt text on the logo and icons; empty alt on spacers. |
| Images of text | 1.4.5, AA | Use real text rather than images of text. A logotype is an exception. | Never set a phone number as a picture. |
| Link purpose | 2.4.4, A | The purpose of a link can be worked out from its text, or its text and context. “Click here” fails. | Write “Book a 20 minute call”, not “Click here”. |
| Use of colour | 1.4.1, A | Colour is not the only visual way to convey information. | Underline links, or keep them at 3 to 1 against the text around them. |
| Reading order | 1.3.2, A | When order affects meaning, a correct reading sequence can be worked out by software. | Name, role, company, contact, in that order. |
| Target size | 2.5.8, AA | Controls should be at least 24 by 24 CSS pixels, with exceptions such as links inside a sentence. | Social icons at 24 pixels or more, with gaps. |
Contrast in an accessible email signature
The test for ordinary text is 4.5 to 1. The W3C adds that the figure is a threshold: a result of 4.499 to 1 does not pass, and you do not round up. We worked out these pairs with the formula W3C publishes.
| Text on background | Ratio | 13 pixel text |
|---|---|---|
| Dark grey #4a5568 on white | 7.53 | Passes |
| Grey #595959 on white | 7.00 | Passes |
| Grey #6b7280 on white | 4.83 | Passes |
| Grey #777777 on white | 4.48 | Fails, by a hair |
| Grey #718096 on white | 4.02 | Fails |
| Pale grey #999999 on white | 2.85 | Fails |
| White on teal #0c8f8f | 3.93 | Fails |
| White on navy #1e3a6e | 11.14 | Passes |
| Light grey #a4b0c4 on dark #131a28 | 7.95 | Passes |
Check the dark-mode pair as well as the light one. Our article on email signature dark mode covers that, and email signature design has the contrast figures for all of emailfooter’s 24 colour themes, so we do not repeat them here. The email signature colors article helps choose a palette. Two before-and-after signatures below show the difference in a drawn accessible email signature.
Alt text in an accessible email signature
The right alt text depends on what the image does.
| Image | Alt text | Why |
|---|---|---|
| Logo | The company name | It carries the name; WCAG asks for an equivalent. |
| Portrait | Empty if your name is printed beside it, otherwise your name | A duplicate read-out adds nothing. |
| Social icon inside a link | The network, such as “LinkedIn” | Without it, the link has no name. |
| Phone or mail icon beside text | Empty | The text beside it already says it. |
| Divider or spacer | Empty | Decoration; the W3C says it should be ignorable. |
What emailfooter does, from reading its engine code: the logo’s alt text is the company name, the photo’s alt text is the person’s name, social icons take the network name, and the small icons next to phone, email and web lines have empty alt text. One side effect: the photo and the name beside it can be read twice. The engine also adds a hidden second copy of each icon for dark mode. They are hidden with display:none, but we have not tested whether every mail app skips them, so test yours.
To add alt text to your accessible email signature yourself, Microsoft’s page on accessible Outlook email says that in Outlook for Windows you right-click the image and choose the alt text option, and in Outlook on the web you right-click the image in the message body and select Add alternate text. It advises short, unambiguous text and avoiding phrases such as “an image of”. Google’s signature page, which we also read, does not mention alt text, so we give no Gmail steps. A banner that has words in it should either say those words in alt text or become real text. See image email signature for the wider image advice.
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Drawn by emailfooter: the logo’s alt text is the company name and each social icon takes its network name. The clinic and person are made up.
Links, colour and order in an accessible email signature
Link text. Contact lines work best when the link is the address itself: the email, the phone number or the website. For anything else, name the action. Microsoft’s page asks authors to avoid generic phrases such as “Click here” and “Learn more”. emailfooter’s booking link says “Book a meeting”, which meets that. Its text icon style, though, shows short letters such as “in” for LinkedIn, which does not describe a destination well. If you use that style, add a plain link of your own.
Colour. If your links are only a different colour from nearby text, WCAG 1.4.1 and its related technique ask for a 3 to 1 contrast between link and text. Underlining is the simpler fix.
Order. Table-based signatures read in source order, which is usually left cell then right cell, top row then next. That usually puts a left-hand photo or logo first, then the text block. Put the name early in the text and keep the contact lines together.
Size. Microsoft suggests familiar sans serif fonts such as Arial or Calibri at 11 point or larger and avoiding all capitals. 11 point is about 15 pixels, so emailfooter’s default of 13 pixels is smaller than that suggestion. The font size is a setting, so raise it for any audience that needs it.
An accessible email signature, before and after
In this pair, the first signature uses a sky-blue title at 11 pixels, which gives about 2.8 to 1 on white. The second uses navy at 15 pixels.
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Before: sky accent at 11 pixels. Small, pale and below 4.5 to 1. The practice and person are made up.
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After: navy accent at 15 pixels, about 11 to 1 on white. Same words. The practice and person are made up.
Testing an accessible email signature
- Send it to yourself and zoom the message to 200 percent. Does anything overlap or vanish?
- Turn images off. Microsoft’s page on picture downloads says classic Outlook blocks automatic picture downloads by default, so many readers see your signature without its logo. The text must still stand on its own.
- Listen to it. Turn on the screen reader that ships with your computer or phone, open the message, and note the order and the names of the links.
- View it as plain text. Microsoft’s message-format page says plain text cannot show pictures inside the message, so every key detail should exist as text.
- Check dark mode.
For a team, fix the template once, so every accessible email signature starts from the same readable colours and font size. A tool such as emailfooter lets the company admin choose colours, font size and logo for everyone, and each person only edits their own details. It does not install signatures for people, so remind them to re-install after a change.
Frequently asked questions
What makes an accessible email signature?
It has readable colours, alt text that fits each image, descriptive links, real text for every detail, and a sensible reading order.
How do I add alt text to an email signature?
In Outlook for Windows, right-click the image and choose the alt text option. In Outlook on the web, right-click the image and select Add alternate text. Google’s signature page does not mention alt text.
What contrast ratio does an accessible email signature need?
WCAG 1.4.3 asks for 4.5 to 1 for normal text and 3 to 1 for large text. A 13 pixel signature line counts as normal text.
Is an email signature covered by WCAG?
W3C describes WCAG as a standard for web content that can also be applied to non-web technology. Whether a law requires it for email is outside what we read.
Should a phone number be an image in my signature?
No. WCAG 1.4.5 prefers real text to images of text, and an image may not load in the reader’s mail app.
Keep reading
- Email signature design: layout, spacing, colour and hierarchy rules: Email signature design as a one-page spec: width, grid, type scale, spacing and colour count, plus two before-and-after redesigns and a contrast check.
- Email signature in dark mode: fix invisible logos and unreadable text: Email signature dark mode fixes: why logos vanish and text fades, how to repair both, and a test routine for Gmail, Outlook and Apple Mail.
Make every signature in your company match
emailfooter is a free WordPress plugin. You design the signature once, and each person adds their own details and installs it in their mail app. Prefer not to run a website? emailfooter Managed is the same software, hosted for you.