Skip to content

Latest commit

 

History

History
87 lines (61 loc) · 8.02 KB

README.md

File metadata and controls

87 lines (61 loc) · 8.02 KB

Visionary Image

React image component with built-in Blurhash placeholders for better UX and Core Web Vitals.

GitHub Release GitHub Actions Workflow Status npm package size (minzipped, via Bundlephobia) NPM Downloads Storybook demo

Features

  • Easy Blurhash: Get started with Blurhash in 60 seconds.
  • Layout stability: Eliminates Cumulative Layout Shift (CLS) with true-to-size, responsive placeholders.
  • Automatic lazy loading: Off-screen images are deferred, reducing initial pageload size and optimizing Interaction to Next Paint (INP).
  • Lighning-fast previews: Renders placeholders early (by initial DOM layout) using URL-embedded Blurhash data, powered by visionary-url.
  • Framework tested: Compatible with Remix, Next.js, and Vite and supports both client and server-side rendering (SSR, SSG).
  • Additional features: Prevent image dragging; prevent user selecting image
  • Developer friendly: Written in Typescript and unit tested.
  • Search performance: Enhance search ranking potential by improving Core Web Vitals scores.

    "We highly recommend site owners achieve good Core Web Vitals for success with Search" — Google Search Central

Lighthouse Performance

Lighthouse report filmstrip showing three-layer image loading process Lighthouse report loading stage filmstrip

Installation

Install via npm, yarn, or pnpm.

npm install --save visionary-image

Usage

Begin by creating a Visionary image URL. This is then passed to the src prop of the Image component.

Creating a Visionary Image URL

There are several ways to create a Visionary URL.

  1. Use the Visionary URL Maker for public image URLs
  2. Use the Drag & Drop Blurhash Generator for local image files
  3. Use visionary-url to programmatically generate a URL

Render Image

import { Image } from "visionary-image";

const ImageDetails = () => <Image alt="..." src="<Visionary URL>" />;

Component Props

Name Description
alt
string
Image alt tag. Adding alt text to images is highly recommended to accommodate accessible devices and improve discoverability.
bgColorAlpha
number
Base layer (background color) alpha channel.
Default: 0.7
className
string
Classname applied to the container div or the fallback img element.
debug
boolean
Prints handy debug info to the console (Visionary URL data, render times).
disableBlurLayer
boolean
Disables rendering of the blur (canvas) layer.
disableImageLayer
boolean
Disables rendering of the image layer.
height
number, string
If set, will override internally computed image height. By default, Visionary renders optimally sized images, using the aspect-ratio and max-width placeholder data.
hideImageLayer
boolean
Hides the image layer, revealing the blur layer underneath.
lazy
boolean
Should image load lazily.
Default: true
onClick
function
Callback function to invoke when the image is clicked. function.
onError
function
Error callback function.
onLoad
function
Image loaded callback function.
preventDrag
boolean
Prevents user from dragging the image element.
preventSelection
boolean
Prevents user from highlighting the image element.
punch
number
Blurhash punch parameter.
Default: 1
src
string
Visionary URL, Visionary Code, or ordinary image URL.
If src contains Visionary data, placeholders will be rendered, otherwise falls back to an img element.
required
width
number, string
If set, will override internally computed image width. By default, Visionary renders optimally sized images, using the aspect-ratio and max-width placeholder data.

Relevant Questions

Do image placeholders render server-side?

Yes, Visionary Image supports server-side rendering (SSR) and static site generation (SSG), as well as client-side rendering. In server-rendered scenarios, the first layer (background color) renders immediately, followed by the Blurhash and image layers once the page loads in the client's browser.

How long does the Blurhash canvas take to load?

Canvas operations are highly efficient in modern browsers. Rendering the 24x24 pixel Blurhash placeholder typically takes around 1ms.

What is Blurhash and where can I learn more?

Blurhash uses Discrete Cosine Transforms to represent a color-accurate image placeholder as a compact string (in 20-30 characters). Check out the official Blurhash docs for more info.