# openseadragon/openseadragon

An open-source, web-based viewer for zoomable images, implemented in pure JavaScript.

Repository: https://github.com/openseadragon/openseadragon
Canonical: https://ross.abutalabs.com/products/openseadragon
Homepage: http://openseadragon.github.io/
Language: JavaScript
License: BSD-3-Clause
License Family: permissive
Topics: image-viewer, javascript, zooming, high-resolution, image, viewer, iiif
Last push: 2026-08-26T17:21:18+00:00

## Health v2 (maintenance only)
Score: 94/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 99, release rhythm 84, longevity 100
- inputs: {"age_days": 4962, "days_push": 7, "days_rel": 27, "gap_med": 81.5, "n_releases_24m": 5}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3500, forks 701 (observed 2026-08-28T04:08:07.472100+00:00)

## What it is
OpenSeadragon is an open-source, web-based viewer for high-resolution zoomable images, implemented in pure JavaScript for desktop and mobile. It supports multiple tile source protocols including DZI, IIIF, Zoomify, TMS, and OpenStreetMap, and is extensible via plugins.

## Use cases
- display zoomable high-resolution images in the browser
- embed a IIIF image viewer in a digital library or archive site
- view deep zoom DZI images on desktop and mobile
- build a map-like tiled image viewer with pan and zoom
- view large microscopy or scanned document images on the web
- add smooth zoomable image galleries to a website

## When to choose
- you need to serve very large or high-resolution images with smooth zooming in a web app
- your images come from IIIF, DZI, Zoomify, TMS, or OSM tile servers
- you need a pure JavaScript, dependency-free viewer that works on desktop and mobile
- you want an extensible viewer with a plugin ecosystem and custom tile source support

## When to avoid
- you only need to display small static images without zoom or pan
- you need server-side image processing or tiling generation (OpenSeadragon only views pre-tiled images)
- you need a native mobile or desktop application rather than a web-based viewer

## Facets
- artifact type: library
- maturity: stable
- function: image-processing, ui-components, frontend-framework
- domain: web-development, frontend, graphics, image-processing
- platform: browser, cross-platform
- tags: zoomable-images, deep-zoom, iiif, image-viewer, tile-sources, pan-and-zoom, high-resolution-images, javascript, mobile

## Member repositories
- openseadragon/openseadragon (main) score 94

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:07.472100+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 2026-08-29T18:35:48.961336+00:00, confidence not recorded.
  - readme: https://github.com/openseadragon/openseadragon (fetched 2026-08-28T04:08:07.472100+00:00, sha 44554f8110f0)
  - homepage: http://openseadragon.github.io/ (fetched 2026-08-29T09:30:02.439260+00:00, sha 386c77fce91b)
  - registry_npm: https://registry.npmjs.org/openseadragon (fetched 2026-08-29T09:30:02.448890+00:00, sha e871cdbb2c8c)
- Data as of 2026-08-30T08:39:29.467469+00:00.