# blueimp/JavaScript-Canvas-to-Blob

JavaScript Canvas to Blob is a function to convert canvas elements into Blob objects.

Repository: https://github.com/blueimp/JavaScript-Canvas-to-Blob
Canonical: https://ross.abutalabs.com/products/javascript-canvas-to-blob
Homepage: https://blueimp.github.io/JavaScript-Canvas-to-Blob/test/
Language: JavaScript
License: MIT
License Family: permissive
Last push: 2021-09-25T16:15:31+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 5318, "days_push": 1803, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1470, forks 385 (observed 2026-08-28T04:04:49.222460+00:00)

## What it is
A zero-dependency JavaScript polyfill for the standard HTMLCanvasElement.toBlob method, converting canvas elements into Blob objects. It enables canvas-to-Blob functionality in older browsers lacking native support.

## Use cases
- convert canvas to blob for file uploads
- polyfill canvas.toBlob in older browsers
- create multipart form data from canvas images
- export canvas drawings as jpeg or png files
- save canvas content as an image file

## When to choose
- you need to support legacy browsers without native toBlob support
- you want a tiny, zero-dependency canvas-to-Blob utility
- you're uploading canvas-generated images via FormData

## When to avoid
- your target browsers all natively support HTMLCanvasElement.toBlob
- you need advanced image processing beyond canvas-to-Blob conversion

## Facets
- artifact type: library
- maturity: maintenance
- function: image-processing, file-upload
- domain: web-development, frontend, image-processing
- platform: browser
- tags: polyfill, canvas, blob, zero-dependencies, javascript

## Member repositories
- blueimp/JavaScript-Canvas-to-Blob (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:49.222460+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 2026-08-30T04:34:48.753372+00:00, confidence not recorded.
  - readme: https://github.com/blueimp/JavaScript-Canvas-to-Blob (fetched 2026-08-28T04:04:49.222460+00:00, sha ba36d2efa49e)
  - homepage: https://blueimp.github.io/JavaScript-Canvas-to-Blob/test/ (fetched 2026-08-29T11:43:03.573489+00:00, sha a2b2f03c3dc5)
- Data as of 2026-08-30T08:39:29.467469+00:00.