# openalpr/openalpr

Automatic License Plate Recognition library

Repository: https://github.com/openalpr/openalpr
Canonical: https://ross.abutalabs.com/products/openalpr
Homepage: http://www.openalpr.com
Language: C++
License: AGPL-3.0
License Family: copyleft
Last push: 2024-01-11T02:23:51+00:00

## Health v2 (maintenance only)
Score: 23/100 (v2, computed 2026-09-03T02:39:23.370411+00:00)
- activity 0, release rhythm 8, longevity 100
- inputs: {"age_days": 4680, "days_push": 966, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 11452, forks 2502 (observed 2026-08-28T04:10:48.168478+00:00)

## What it is
OpenALPR is an open-source Automatic License Plate Recognition (ALPR) library written in C++ that analyzes images and video streams to detect and read license plates. It ships with a command-line utility and bindings for C#, Java, Node.js, Go, and Python, supporting US and European plate formats.

## Use cases
- read license plate numbers from images
- detect license plates in video streams
- recognize license plates from security camera footage
- build a parking access control system
- identify vehicle plates for law enforcement hotlists
- extract plate text as JSON from photos

## When to choose
- you need self-hosted, offline license plate recognition without subscription fees
- you want a C++ library with bindings for multiple languages
- you need a simple CLI to batch-process plate images
- you only need US or EU plate formats and basic OCR accuracy

## When to avoid
- you need recognition for plates outside US/EU regions
- you want vehicle make, model, and color detection, which is only in the commercial Rekor products
- you need actively developed features or modern deep-learning accuracy
- your project cannot comply with the AGPL-3.0 license

## Facets
- artifact type: library
- maturity: maintenance
- function: computer-vision, image-processing, ocr, machine-learning
- domain: computer-vision, image-processing, security
- platform: windows, cpp, python, go, jvm, dotnet, cli
- tags: license-plate-recognition, alpr, anpr, lpr, video-streams, vehicle-recognition, linux, macos, nodejs

## Member repositories
- openalpr/openalpr (main) score 23

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:10:48.168478+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 2026-08-29T17:15:35.211187+00:00, confidence not recorded.
  - readme: https://github.com/openalpr/openalpr (fetched 2026-08-28T04:10:48.168478+00:00, sha cd83e8624485)
  - homepage: http://www.openalpr.com (fetched 2026-08-29T08:14:19.849240+00:00, sha fd8574676014)
  - site_page: https://www.openalpr.com/software/scout (fetched 2026-08-29T08:14:19.858568+00:00, sha 85414c5c8b6b)
  - site_page: https://www.openalpr.com/software/carcheck (fetched 2026-08-29T08:14:19.860537+00:00, sha a28130f2dd77)
  - site_page: https://www.openalpr.com/use-cases (fetched 2026-08-29T08:14:19.862250+00:00, sha c51507131564)
- Data as of 2026-08-30T08:39:29.467469+00:00.