Miscellaneous code snippets for web developers because you can't memorize everything.
Basic HTML to start a website
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta name="description" content="Description of around 200 letters">
<link rel="stylesheet" href="style.css">
<script async src='script.js'></script>
</head>
<body>
</body>
</html>If your site is not English, don't forget to change the lang attribute.
Make your HTML more semantic by using the right elements.
| element | description |
|---|---|
| main | Main content of the page, without header and footer etcetera |
| article | Part of the page that could stand alone |
| section | Group related elements together |
| header | Title, subtitle, author, publication date |
| footer | Copyright, privacy statement, contact data |
| nav | Page and site navigation with links |
| aside | Content that's supplementary to the main content |
You can add an aria-label attribute to describe the section.
Use the autocomplete attribute in your forms so that users can easily fill them out.
Use one of the following values for the autocomplete attribute to enable the user the auto fill them.
See list of autocomplete attribute values
name honorific-prefix given-name additional-name family-name honorific-suffix nickname organization-title username new-password current-password one-time-code organization street-address address-line1 address-line2 address-line3 address-level4 address-level3 address-level2 address-level1 country country-name postal-code cc-name cc-given-name cc-additional-name cc-family-name cc-number cc-exp cc-exp-month cc-exp-year cc-csc cc-type transaction-currency transaction-amount language bday bday-day bday-month bday-year sex url photo tel tel-country-code tel-national tel-area-code tel-local tel-local-prefix tel-local-suffix tel-extension email impp
For addresses, you can also add shipping and billing and for phone numbers, you can add home, work, mobile, fax or pager.
<input name="shipping-pc" autocomplete="shipping postal-code">Using new-password and current-password is especially important to make a site work nicely with password managers.
When using new-password, you can use the non standard passwordrules attribute to specify the rules for a valid password.
See Apple's Password Rules Validation Tool.
See the autofill attribute specification for all possibilities.
Box sizing border box is easier to work with.
html {
box-sizing: border-box;
}
*,
*::before,
*::after {
box-sizing: inherit;
}Turn on hyphenation for the right elements only.
body {
-webkit-hyphens: auto;
hyphens: auto;
}
code, var, kbd, samp, tt, dir,
abbr, acronym, blockquote, q {
-webkit-hyphens: none;
hyphens: none;
}You can put a favicon.ico in the root of your site and call it a day.
Make sure favicon.ico contains both a 16×16 and 32×32 icon.
If you want to provide an SVG, you can use the code below.
<link rel="icon" href="/favicon.ico" sizes="48x48" >
<link rel="icon" href="/favicon.svg" sizes="any" type="image/svg+xml">See Definitive edition of "How to Favicon" in 2023 by Masa Kudamatsu for more in depth information.
Show an image and description when sharing on social media (Facebook, Twitter, LinkedIn, etcetera).
<meta name="description"
content="Description of max 200 characters">
<meta property="og:image" content="https://url-to-image">
<meta property="og:image:width" content="476">
<meta property="og:image:height" content="249">
<meta property="og:image:alt" content="Description of image">By default the page title will be taken from the title element, which often looks like "Page Title - Site Name". With meta tags, the page title and site name can be defined separately:
<meta property="og:title" content="Page Title">
<meta property="og:site_name" content="Site Name">See the Open Graph protocol for all possible metadata.
Make your website behave like an app. With the code below, a user can add the website to their desktop or home screen and open it as an app without the browser chrome (so, no address bar etcetera).
In your root directory, you need these two files:
apple-touch-icon.png - The app icon with a minimal size of 192×192px
manifest.json - Contains metadata of the app, see below
This is example content of the manifest.json file:
{
"short_name": "App name",
"name": "Full name of the app",
"start_url": "https://example.com/",
"description": "Description of the app: what does it do?",
"icons": [
{
"src": "/apple-touch-icon.png",
"sizes": "192x192",
"type": "image/png"
}
],
"display": "standalone",
"background_color": "#ffcccc",
"theme_color": "#ccccff",
"categories": ["weblog"]
}See MDN: Web app manifests for more options.
Now refer to these files from your HTML:
<link rel="manifest" href="/manifest.json"/>
<link rel="apple-touch-icon" href="/apple-touch-icon.png"/>
<meta name="theme-color" content="#ccccff">You can make your site more app like by adding offline capabilities. See Make your PWA feel more like an app for more ideas.
Simple CSS animation using transform and transition.
.block {
transform: translateX(0);
transition: all 250ms ease;
}
.block.moved {
transform: translateX(200px);
}For good performance, only animate transform and opacity.
If performance is still not good, take a look at
the will-change property.
In CSS, you can't just animate any element to auto height. By using a grid row, you can.
.container {
display: grid;
grid-template-rows: 0fr;
transition: grid-template-rows 250ms;
}
.container > .inner {
overflow: hidden;
}
.container:hover {
grid-template-rows: 1fr;
}Improve the accessibility of your website by reducing animations when requested:
@media (prefers-reduced-motion) {
* {
transition-property: none;
}
}Or increase contrast:
html {
color: #ccc;
background-color: white;
}
@media (prefers-contrast: more) {
html {
color: black;
}
}Note: make sure contrast is always good, even without this media query.
Define a custom font. All modern browsers support WOFF2.
@font-face {
font-family: MavenPro;
src: url('fonts/mavenpro/maven_pro_bold-webfont.woff2') format('woff2');
font-weight: bold;
font-style: normal;
font-display: swap;
}Which font weight number belongs to which font weight name.
| css | name |
|---|---|
| 100 | Thin |
| 300 | Light |
| 350 | Book |
| 400 (normal) | Normal/Regular |
| 500 | Medium |
| 600 | Semi Bold/Demi Bold |
| 700 (bold) | Bold |
| 800 | Extra Bold/Ultra Bold |
| 900 | Black/Heavy |
Every webpage should look good on desktop, tablet and mobile.
/* Mobile */
.box {
padding: 10px;
}
/* Tablet */
@media screen and (min-width: 768px) {
.box {
padding: 40px;
}
}
/* Desktop */
@media screen and (min-width: 1024px) {
.box {
padding: 80px;
}
}Adjust the styling of UI elements and interactions.
div {
accent-color: lime; /* Color of UI elements */
caret-color: blue; /* Color of caret (text cursor) */
}
div::selection { /* Styling of selected text */
color: black;
background-color: orange;
}Switch your color scheme to match the light or dark mode of the user.
html {
color: black;
background-color: white;
}
@media (prefers-color-scheme: dark) {
html {
color: white;
background-color: black;
}
}If you have your own toggle, then don't forget to set the color-scheme property, so UI elements will adapt to the theme.
Change the color of svg's with CSS. If you have multiple svg's, you can use svg-sprite to combine them in one single svg using the view mode.
npx svg-sprite --view --view-bust false --view-example --dest=dest assets/icons/*.svgIf one of your svg-files is called mail.svg, you can show the icon using this class:
.mail-icon {
width: 24px;
height: 24px;
background: currentColor;
mask-image: url(dest/sprites.svg#mail);
mask-size: contain;
}In this case, the icon gets the same color as the surrounding text, but you can apply any gradient or background image you want.
<span class="mail-icon"></span>Instead of wrapping a text, show an ellipsis (…)
.text {
width: 200px;
white-space: nowrap;
overflow: hidden;
text-overflow: ellipsis;
}Use line clamp but for multiple lines.
.box {
display: -webkit-box;
-webkit-box-orient: vertical;
overflow: hidden;
-webkit-line-clamp: 3;
line-clamp: 3;
}Also works with other (ui) elements.
button.my-style {
padding: 0;
border: none;
background-color: transparent;
/* my styles… */
}You can also reset all styles. Note that this also removes your own inherited styles.
button.my-style {
all: initial;
/* my styles… */
}Use flexbox to show text at the top of the button, to make it exchangeable with a <div>.
button.my-style {
/* other reset styles… */
display: inline-flex;
align-items: flex-start;
/* my styles… */
}Don't show focus outlines for mouse users. Note that <input> and <textarea> will always apply the focus-visible style.
Use transparent as a standard color, as this will become visible in high contrast mode.
* {
outline-color: transparent;
}
:focus-visible {
outline: 1px solid #00A1F1;
}Some devices like mobiles might not have hover and change the style to compensate.
div {
/* styles when hover is not supported */
}
@media (hover) {
div {
/* styles when hover is supported */
}
div:hover {
/* styles with hover */
}
}| property | value | use |
|---|---|---|
| touch-action | manipulation | Prevent click delay by not waiting for possible double click |
| pointer-events | none | Make a top level element behave like it's not there |
| object-fit | cover | Specify how an image should be shown in an img element |
| user-select | none | Prevents text to be selected |
| aspect-ratio | 9 / 16 | Specify aspect ratio of the element |
Note
Don't include text in this element.
<div class="background-image" role="img" aria-label="Alt text"></div>The aria-label attribute has much more uses.
Remove the semantics from an element
<h2 role="presentation">Large text, but not a heading</h2>Don't highlight the current page in a table of contents by only changing the class but use aria-current.
<ol>
<li><a href="…">Some page</a></li>
<li aria-current="page">Some other page</li>
</ol>Then style the current page entry in the table as contents as follows
[aria-current="page"] {
font-weight: bold;
}aria-current can have the following values: page, step, location, date, time, true and false.
See MDN: aria-current
for a detailed explanation.
Make it clear when buttons are toggled on or off.
<ol role="tablist">
<li><button role="tab" aria-selected="false">One</button></li>
<li><button role="tab" aria-selected="true">Two</button></li>
</ol>Then you can also use the aria-selected attribute for styling:
[aria-selected='true'] {
background-color: mintcream;
}See also WAI-ARIA Authoring Practices
You can style the scrollbar, but this is very browser and operating system dependent,
so test where necessary.
Apply both classes (scrollbar-style1 and styled-scrollbar) to your container.
/* Custom style with configurable parameters */
.scrollbar-style1 {
overflow: auto; /* enable automatic scrollbars */
scrollbar-width: thin; /* none, thin or auto (Firefox) */
--scrollbar-size: 8px; /* 8px when using thin (Webkit) */
--scrollbar-color: lightblue;
--scrollbar-thumb-color: blue;
--scrollbar-thumb-rect: 1; /* add this line for a rectangular thumb (Webkit) */
}
/* You can leave the code below as is */
.styled-scrollbar {
scrollbar-color: var(--scrollbar-thumb-color) var(--scrollbar-color, transparent);
}
/* WebKit and Chromiums */
.styled-scrollbar::-webkit-scrollbar {
width: var(--scrollbar-size);
height: var(--scrollbar-size);
background-color: var(--scrollbar-color);
}
.styled-scrollbar::-webkit-scrollbar-thumb {
background: var(--scrollbar-thumb-color);
border-radius: calc(99px - var(--scrollbar-thumb-rect, 0) * 99px);
}
If your site has an RSS (or Atom) feed, make it discoverable for RSS readers. Put the following code in your HTML head.
Example for an RSS feed:
<link rel="alternate" type="application/rss+xml" title="My site name" href="https://example.com/feed.rss.xml" />Example for an Atom feed:
<link rel="alternate" type="application/atom+xml" title="My site name" href="https://example.com/feed.atom.xml" />Even when a site looks fine on first glance, it can still be broken. Check the list below to make sure the site is really ready to be published.
- Check the site in Google Lighthouse and make sure the score is good
- Is the site SEO friendly? Can it be found with search engines?
- Test the site on various mobile devices (phones and tablets)
- Has a proper 404 page been set up for when a invalid url is requested?
- Some jurisdictions require contact/about/legal info pages
- The back button always goes to the previous page
- Is the text easy to read?
- Can you use the site with keyboard only?
- Does the site still work when the text is enlarged? (CTRL-+ or Command-+)
- Form fields use the autocomplete attribute
- Every page has a different title (with the generic part at the end)
- Don't forget the favicon
- Add an image and description for when the site is shared on social media
- Add a print style sheet for when it is expected the pages will be printed
- Add the lang attribute
- For international sites in one language: the site works with browser autotranslation
Some symbols are hard to type and sometimes you want to know the HTML entity code.
| name | entity code | character |
|---|---|---|
| Degree sign | ° | ° |
| Horizontal ellipsis | … | … |
| Bullet | • | • |
| Multiplication sign | × | × |
| Euro sign | € | € |
| Single left quotation mark | ‘ | ‘ |
| Single right quotation mark | ’ | ’ |
| Single low-9 quotation mark | ‚ | ‚ |
| Double left quotation mark | “ | “ |
| Double right quotation mark | ” | ” |
| Double low-9 quotation mark | „ | „ |
See also Character Entity Reference Chart
Copy and paste placeholder text.
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Pellentesque varius sem sed nibh pharetra, id ultricies justo sodales. Integer convallis magna lobortis, pulvinar massa et, egestas risus. Nunc ultrices eget nibh convallis auctor. Sed at luctus felis, nec fringilla ante. Aenean facilisis urna eget pellentesque posuere. Maecenas faucibus sem sit amet diam euismod, mollis bibendum quam ornare. Quisque finibus arcu quis molestie pulvinar. Duis sed aliquam nibh, ut pharetra felis. Aenean vel fermentum risus, ac tincidunt enim. Class aptent taciti sociosqu ad litora torquent per conubia nostra, per inceptos himenaeos. Quisque elementum sit amet libero sed accumsan. Duis nec nunc nec dolor posuere pulvinar. Quisque suscipit congue mi, sed imperdiet libero laoreet non. In sed sodales neque, in bibendum lectus.
Ut nec posuere ipsum. Sed sagittis malesuada dui a blandit. Mauris consectetur consectetur laoreet. Sed erat quam, semper non euismod ut, consequat vitae neque. Sed sodales lorem quis erat iaculis, tristique varius diam tincidunt. Sed venenatis ipsum nec accumsan bibendum. Nulla ac felis sit amet ipsum feugiat viverra non eget erat. Maecenas enim nulla, vehicula eu purus id, lacinia tincidunt leo. Interdum et malesuada fames ac ante ipsum primis in faucibus. Class aptent taciti sociosqu ad litora torquent per conubia nostra, per inceptos himenaeos. Nulla facilisi. Aliquam suscipit interdum massa. Integer sit amet tincidunt nulla. Proin et ante felis. Pellentesque mauris orci, rutrum sed massa vel, lobortis consequat justo.