Preload key requests

Consider using `<link rel=preload>` to prioritize fetching resources that are currently requested later in page load.

Preload Largest Contentful Paint image

Preload the image used by the LCP element in order to improve your LCP time.

Avoid chaining critical requests

The Critical Request Chains below show you what resources are loaded with a high priority. Consider reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load.

User Timing marks and measures

Consider instrumenting your app with the User Timing API to measure your app's real-world performance during key user experiences.

Performance budget

Keep the quantity and size of network requests under the targets set by the provided performance budget.

Timing budget

Set a timing budget to help you keep an eye on the performance of your site. Performant sites load fast and respond to user input events quickly.

Keep request counts low and transfer sizes small

To set budgets for the quantity and size of page resources, add a budget.json file.

Lazy load third-party resources with facades

Some third-party embeds can be lazy loaded. Consider replacing them with a facade until they are required.

Largest Contentful Paint element

This is the largest contentful element painted within the viewport. [Learn More](https://web.dev/lighthouse-largest-contentful-paint/)

Avoid large layout shifts

These DOM elements contribute most to the CLS of the page.

Avoid long main-thread tasks

Lists the longest tasks on the main thread, useful for identifying worst contributors to input delay.

Avoid non-composited animations

Animations which are not composited can be janky and increase CLS.

Image elements have explicit `width` and `height`

Set an explicit width and height on image elements to reduce layout shifts and improve CLS.

Network Requests

Lists the network requests that were made during page load.

Network Round Trip Times

Network round trip times (RTT) have a large impact on performance. If the RTT to an origin is high, it's an indication that servers closer to the user could improve performance.

Server Backend Latencies

Server latencies can impact web performance. If the server latency of an origin is high, it's an indication the server is overloaded or has poor backend performance.

Tasks

Lists the toplevel main thread tasks that executed during page load.

Diagnostics

Collection of useful page vitals.

Metrics

Collects all available metrics.

Screenshot Thumbnails

This is what the load of your site looked like.

Final Screenshot

The last screenshot captured of the pageload.

Script Treemap Data

Used for treemap app

`[accesskey]` values are unique

Access keys let users quickly focus a part of the page. For proper navigation, each access key must be unique.

`[aria-*]` attributes match their roles

Each ARIA `role` supports a specific subset of `aria-*` attributes. Mismatching these invalidates the `aria-*` attributes.

`button`, `link`, and `menuitem` elements have accessible names

When an element doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers.

`[aria-hidden="true"]` elements do not contain focusable descendents

Focusable descendents within an `[aria-hidden="true"]` element prevent those interactive elements from being available to users of assistive technologies like screen readers.

ARIA input fields have accessible names

When an input field doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers.

ARIA `meter` elements have accessible names

When an element doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers.

ARIA `progressbar` elements have accessible names

When a `progressbar` element doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers.

Elements with an ARIA `[role]` that require children to contain a specific `[role]` have all required children.

Some ARIA parent roles must contain specific child roles to perform their intended accessibility functions.

`[role]`s are contained by their required parent element

Some ARIA child roles must be contained by specific parent roles to properly perform their intended accessibility functions.

ARIA toggle fields have accessible names

When a toggle field doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers.

ARIA `tooltip` elements have accessible names

When an element doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers.

ARIA `treeitem` elements have accessible names

When an element doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers.

`[aria-*]` attributes have valid values

Assistive technologies, like screen readers, can't interpret ARIA attributes with invalid values.

`[aria-*]` attributes are valid and not misspelled

Assistive technologies, like screen readers, can't interpret ARIA attributes with invalid names.

Buttons have an accessible name

When a button doesn't have an accessible name, screen readers announce it as "button", making it unusable for users who rely on screen readers.

`<dl>`'s contain only properly-ordered `<dt>` and `<dd>` groups, `<script>`, `<template>` or `<div>` elements.

When definition lists are not properly marked up, screen readers may produce confusing or inaccurate output.

Definition list items are wrapped in `<dl>` elements

Definition list items (`<dt>` and `<dd>`) must be wrapped in a parent `<dl>` element to ensure that screen readers can properly announce them.

`[id]` attributes on active, focusable elements are unique

All focusable elements must have a unique `id` to ensure that they're visible to assistive technologies.

ARIA IDs are unique

The value of an ARIA ID must be unique to prevent other instances from being overlooked by assistive technologies.

No form fields have multiple labels

Form fields with multiple labels can be confusingly announced by assistive technologies like screen readers which use either the first, the last, or all of the labels.

`<frame>` or `<iframe>` elements have a title

Screen reader users rely on frame titles to describe the contents of frames.

`<html>` element has a valid value for its `[lang]` attribute

Specifying a valid [BCP 47 language](https://www.w3.org/International/questions/qa-choosing-language-tags#question) helps screen readers announce text properly.

Image elements have `[alt]` attributes

Informative elements should aim for short, descriptive alternate text. Decorative elements can be ignored with an empty alt attribute.

`<input type="image">` elements have `[alt]` text

When an image is being used as an `<input>` button, providing alternative text can help screen reader users understand the purpose of the button.

Form elements have associated labels

Labels ensure that form controls are announced properly by assistive technologies, like screen readers.

The document does not use `<meta http-equiv="refresh">`

Users do not expect a page to refresh automatically, and doing so will move focus back to the top of the page. This may create a frustrating or confusing experience.

`[user-scalable="no"]` is not used in the `<meta name="viewport">` element and the `[maximum-scale]` attribute is not less than 5.

Disabling zooming is problematic for users with low vision who rely on screen magnification to properly see the contents of a web page.

`<object>` elements have `[alt]` text

Screen readers cannot translate non-text content. Adding alt text to `<object>` elements helps screen readers convey meaning to users.

No element has a `[tabindex]` value greater than 0

A value greater than 0 implies an explicit navigation ordering. Although technically valid, this often creates frustrating experiences for users who rely on assistive technologies.

Cells in a `<table>` element that use the `[headers]` attribute refer to table cells within the same table.

Screen readers have features to make navigating tables easier. Ensuring `<td>` cells using the `[headers]` attribute only refer to other cells in the same table may improve the experience for screen reader users.

`<th>` elements and elements with `[role="columnheader"/"rowheader"]` have data cells they describe.

Screen readers have features to make navigating tables easier. Ensuring table headers always refer to some set of cells may improve the experience for screen reader users.

`<video>` elements contain a `<track>` element with `[kind="captions"]`

When a video provides a caption it is easier for deaf and hearing impaired users to access its information.

The page has a logical tab order

Tabbing through the page follows the visual layout. Users cannot focus elements that are offscreen.

Interactive controls are keyboard focusable

Custom interactive controls are keyboard focusable and display a focus indicator.

Interactive elements indicate their purpose and state

Interactive elements, such as links and buttons, should indicate their state and be distinguishable from non-interactive elements.

The user's focus is directed to new content added to the page

If new content, such as a dialog, is added to the page, the user's focus is directed to it.

User focus is not accidentally trapped in a region

A user can tab into and out of any control or region without accidentally trapping their focus.

Custom controls have associated labels

Custom interactive controls have associated labels, provided by aria-label or aria-labelledby.

Custom controls have ARIA roles

Custom interactive controls have appropriate ARIA roles.

Visual order on the page follows DOM order

DOM order matches the visual order, improving navigation for assistive technology.

Offscreen content is hidden from assistive technology

Offscreen content is hidden with display: none or aria-hidden=true.

HTML5 landmark elements are used to improve navigation

Landmark elements (<main>, <nav>, etc.) are used to improve the keyboard navigation of the page for assistive technology.

Ensure CSP is effective against XSS attacks

A strong Content Security Policy (CSP) significantly reduces the risk of cross-site scripting (XSS) attacks.

Fonts with `font-display: optional` are preloaded

Preload `optional` fonts so first-time visitors may use them.

Site works cross-browser

To reach the most number of users, sites should work across every major browser.

Page transitions don't feel like they block on the network

Transitions should feel snappy as you tap around, even on a slow network. This experience is key to a user's perception of performance.

Each page has a URL

Ensure individual pages are deep linkable via URL and that URLs are unique for the purpose of shareability on social media.