# Viewer.js

JavaScript image viewer.

Repository: https://github.com/fengyuanchen/viewerjs
Canonical: https://ross.abutalabs.com/products/viewerjs
Homepage: https://fengyuanchen.github.io/viewerjs/
Language: JavaScript
License: MIT
License Family: permissive
Topics: javascript, viewer, image, image-viewer
Last push: 2026-08-23T09:42:33+00:00
Link (homepage): https://fengyuanchen.github.io/viewerjs/

## Health v2 (maintenance only)
Score: 95/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 99, release rhythm 87, longevity 100
- inputs: {"age_days": 3905, "days_push": 10, "days_rel": 11, "gap_med": 33, "n_releases_24m": 4}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 8234, forks 1240 (observed 2026-08-28T04:10:19.757635+00:00)

## What it is
Viewer.js is a JavaScript library for viewing images in the browser with zoom, rotation, flip, move, and keyboard/touch support. It works in modal or inline modes and includes a jQuery plugin wrapper.

## Use cases
- display images in a lightbox with zoom and rotate
- build an image gallery with fullscreen viewing
- add touch-friendly image viewing to a mobile web page
- view a list of images with prev/next navigation
- embed an inline zoomable image viewer in a web app
- flip and rotate product photos in a catalog

## When to choose
- you need a lightweight, dependency-free image viewer for the browser
- you want zoom, rotate, flip, and keyboard/touch support out of the box
- you need both modal and inline viewing modes

## When to avoid
- you need to view non-image formats like PDFs or videos
- you need a full image editor with cropping or annotation
- you are not working in a browser/frontend environment

## Facets
- artifact type: library
- maturity: stable
- function: image-processing, ui-components
- domain: frontend, web-development, media
- platform: browser
- tags: image-viewer, lightbox, zoom, rotate, gallery, touch-support, jquery-plugin, javascript, nodejs

## Member repositories
- fengyuanchen/viewerjs (main) score 95
- fengyuanchen/viewer (plugin) score 10

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:10:19.757635+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:29:30.283992+00:00, confidence not recorded.
  - readme: https://github.com/fengyuanchen/viewerjs (fetched 2026-08-28T04:10:19.757635+00:00, sha bfaed70280f4)
  - homepage: https://fengyuanchen.github.io/viewerjs/ (fetched 2026-08-29T08:28:42.630453+00:00, sha f9de342fc586)
  - registry_npm: https://registry.npmjs.org/viewerjs (fetched 2026-08-29T08:28:42.639966+00:00, sha 4c9106c23e77)
- Data as of 2026-08-30T08:39:29.467469+00:00.