Snapshot API Reference

Welcome to the Plate Recognizer Snapshot API! You can use our API to access our API endpoints, which can read license plates from images.

For detailed instructions on how to use Snapshot Cloud, go here.

For detailed instructions on how to install the Snapshot SDK, go here.

We have multiple language bindings. You can view code examples in various languages when you scroll down.

Other use cases:

If you need to detect vehicles and decode license plates from a live camera or video feed, consider using Plate Recognizer Stream. Contact us to request a Free Trial of Stream.
If you need to blur license plates, consider using Plate Recognizer Blur. Contact us for more information.

Snapshot Cloud API

Authentication

Plate Recognizer Snapshot Cloud is only available to registered users. Sign up for a Free Trial and get an API Token. It has to be included in all API calls. The HTTP headers must contain:

Authorization: Token YOUR_API_TOKEN

danger

For the commands below, make sure to replace YOUR_API_TOKEN with your API Token. For example, Authorization: Token 3a0effff73919f898b69ac65a32dc12347769564.

Get your token from, here.

Read Number Plates from an Image

This Snapshot API endpoint reads all license plates from an image.

tip

By default, we only return vehicles with a license plate. To include vehicles without a license plate, set the engine configuration to {"detection_mode":"vehicle"}.
To programmatically process a bunch of images in a folder, refer to our Snapshot Guides.

HTTP Request

POST https://api.platerecognizer.com/v1/plate-reader/

The CORS policy of this endpoint allows requests from all origins.

POST Parameters

Parameter	Required	Description
upload	Yes	The file to be uploaded. The parameter can either be the file bytes (using Content-Type multipart/form-data) OR a base64 encoded image. This parameter becomes optional if upload_url parameter is present.
upload_url	No	The url of file to be uploaded. This parameter is to be used as an alternative to upload parameter.
regions	No	Match the license plate pattern of specific state(s) or country(ies). Best practice is to indicate the top 3-4 states/countries of vehicle plates that camera will be observing. This optimizes the engine to correctly decode zero vs letter O, one vs letter I, etc. Note that even if a foreign vehicle arrives, engine will still decode that foreign vehicle correctly. Accepts multiple arguments or comma-separated values. See list of states and countries.
camera_id	No	Unique camera identifier.
timestamp	No	ISO 8601 timestamp. For example, 2019-08-19T13:11:25. The timestamp has to be in UTC.
mmc	No	Predict vehicle make, model, orientation and color. This feature is available for an additional fee. Set parameter to true (mmc=true) if you have this feature enabled/purchased to get vehicle make, model and color. Possible values are true or false.
direction	No	Predict vehicle's direction of travel. Set parameter to true (direction=true), also requires mmc=true to work. New in version 1.52.0.
config	No	Additional engine configuration. See details.

tip

Download a free test image from this url. To download using curl:

curl -o /tmp/car.jpg https://app.platerecognizer.com/static/demo.jpg

Linux
Windows

Process an image located at /tmp/car.jpg
curl -X POST -F "upload=@/tmp/car.jpg" \
    -H "Authorization: Token YOUR_API_TOKEN" \
    https://api.platerecognizer.com/v1/plate-reader

Specify 2 regions (Mexico and California).
curl -F "upload=@/tmp/car.jpg" \
    -F regions=`mx` \
    -F regions=us-ca \
    -H "Authorization: Token YOUR_API_TOKEN" \
    https://api.platerecognizer.com/v1/plate-reader/

Custom engine configuration and 2 regions (Mexico and California).
curl -F "upload=@/path/to/car.jpg" \
    -F regions=mx,us-ca \
    -F config="{\"region\":\"strict\"}" \
    -H "Authorization: Token YOUR_API_TOKEN" \
    https://api.platerecognizer.com/v1/plate-reader/

Process an image from a URL.
curl -X POST -F upload_url="https://app.platerecognizer.com/static/demo.jpg" \
    -H "Authorization: Token YOUR_API_TOKEN" \
    https://api.platerecognizer.com/v1/plate-reader

Process an image car.jpg located in the current directory
curl -X POST -F "[email protected]" ^
    -H "Authorization: Token YOUR_API_TOKEN" ^
    https://api.platerecognizer.com/v1/plate-reader

Specify 2 regions (Mexico and California).
curl -F "[email protected]" ^
    -F regions=`mx` ^
    -F regions='us-ca' ^
    -H "Authorization: Token YOUR_API_TOKEN" ^
    https://api.platerecognizer.com/v1/plate-reader/

Custom engine configuration and region California.
    curl -F "upload=@c:\path\to\car.jpg" ^
    -F regions='us-ca' ^
    -F config="{\"region\":\"strict\"}" ^
    -H "Authorization: Token YOUR_API_TOKEN" ^
    https://api.platerecognizer.com/v1/plate-reader/

You may need to install required Gem: gem install multipart-post

upload file using multipart-post
require 'net/http/post/multipart'

url = URI.parse('https://api.platerecognizer.com/v1/plate-reader/')
path = '/path/to/car.jpg'
File.open(path) do |jpg|
  req = Net::HTTP::Post::Multipart.new url.path,
    "upload" => UploadIO.new(jpg, "image/jpeg", path)
  req['Authorization'] = 'Token YOUR_API_TOKEN'
  res = Net::HTTP.start(url.host, url.port, use_ssl: true) do |http|
    http.request(req)
  end
end

Upload using pypi requests module
import requests
from pprint import pprint
regions = ["mx", "us-ca"] # Change to your country
with open('/path/to/car.jpg', 'rb') as fp:
    response = requests.post(
        'https://api.platerecognizer.com/v1/plate-reader/',
        data=dict(regions=regions),  #Optional
        files=dict(upload=fp),
        headers={'Authorization': 'Token YOUR_API_TOKEN'})

pprint(response.json())

Calling with a custom engine configuration
import json
with open('/path/to/car.jpg', 'rb') as fp:
    response = requests.post(
        'https://api.platerecognizer.com/v1/plate-reader/',
        data=dict(regions=['us-ca'], config=json.dumps(dict(region="strict"))),  ## Optional
        files=dict(upload=fp),
        headers={'Authorization': 'Token YOUR_API_TOKEN'})

Using imencode method produces a compressed representation that can be easier stored, transmitted, or processed.

Processing an OpenCV image without writing to disk.
import cv2
success, image_jpg = cv2.imencode('.jpg', image)
files={'upload':image_jpg.tostring()}
response = requests.post(
            'https://api.platerecognizer.com/v1/plate-reader/',
            headers={'Authorization': 'Token YOUR_API_TOKEN'})

If using Node-RED, Check https://github.com/parkpow/node-red-contrib-plate-recognizer

Node-fetch upload
const fetch = require("node-fetch");
const FormData = require("form-data");
const fs = require("fs");

let image_path = "/path/to/car.jpg";
let body = new FormData();
body.append("upload", fs.createReadStream(image_path));
// Or body.append('upload', base64Image);
body.append("regions", "us-ca"); // Change to your country
fetch("https://api.platerecognizer.com/v1/plate-reader/", {
  method: "POST",
  headers: {
    Authorization: "Token YOUR_API_TOKEN",
  },
  body: body,
})
  .then((res) => res.json())
  .then((json) => console.log(json))
  .catch((err) => {
    console.log(err);
  });

PHP Curl with regions upload
  <?php
  // CREATE FILE READY TO UPLOAD WITH CURL
  $file = realpath('example.jpg');
  if (function_exists('curl_file_create')) { // php 5.5+
    $cFile = curl_file_create($file);
  } else {
    $cFile = '@' . realpath($file);
  }

  //ADD PARAMETER IN REQUEST LIKE regions
  $data = array(
      'upload' => $cFile,
      'regions' => 'us-ca' // Optional
  );

  // Prepare new cURL resource
  $ch = curl_init('https://api.platerecognizer.com/v1/plate-reader/');
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
  curl_setopt($ch, CURLINFO_HEADER_OUT, true);
  curl_setopt($ch, CURLOPT_POST, true);
  curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
  curl_setopt($ch, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_2TLS);

  // Set HTTP Header for POST request
  curl_setopt($ch, CURLOPT_HTTPHEADER, array(
      "Authorization: Token YOUR_API_TOKEN"
      )
  );

  // Submit the POST request and close cURL session handle
  $result = curl_exec($ch);
  print_r($result);exit;
  curl_close($ch);
  ?>

Response

JSON Response for detection_mode = plate
JSON Response for detection_mode = vehicle

The response is a list of all the license plates found in the image.

{
  "processing_time": 288.758,
  "results": [
    {
      "box": {
        "xmin": 143,
        "ymin": 481,
        "xmax": 282,
        "ymax": 575
      },
      "plate": "nhk552",
      "region": {
        "code": "gb",
        "score": 0.747
      },
      "vehicle": {
        "score": 0.798,
        "type": "Sedan",
        "box": {
          "xmin": 67,
          "ymin": 113,
          "xmax": 908,
          "ymax": 653
        }
      },
      "score": 0.904,
      "candidates": [
        {
          "score": 0.904,
          "plate": "nhk552"
        }
      ],
      "dscore": 0.99,
      // Make Model, Orientation and Color are only available if you set mmc=true
      "model_make": [
        {
          "make": "Riley",
          "model": "RMF",
          "score": 0.306
        }
      ],
      "color": [
        {
          "color": "black",
          "score": 0.937
        }
      ],
      "orientation": [
        {
          "orientation": "Front",
          "score": 0.937
        }
      ],
      // Direction is only available is you set mmc=true and direction=true
      "direction": 134,
      "direction_score": 0.76
    }
  ],
  "filename": "1617_7M83K_car.jpg",
  "version": 1,
  "camera_id": null,
  "timestamp": "2020-10-12T16:17:27.574008Z"
}

When the parameter detection_mode is set to vehicle, the output includes vehicles without a license plate. The lookup response is as follows:

Each element of the list is now an object with two optional elements: plate and vehicle.
The license plate text is stored in plate.props.plate as a list. The first element is the top prediction.
The license plate region is in plate.props.region.
The vehicle properties (orientation, make model and color) are in vehicle.props. Each include the top 3 predictions.

{
  "filename": "car.jpg",
  "timestamp": "2021-11-23 17:56:47.896406",
  "camera_id": "my-camera",
  "processing_time": 58.184,
  "results": [
    {
      "plate": {
        "type": "Plate",
        "score": 0.925,
        "box": {
          "xmin": 146,
          "ymin": 481,
          "xmax": 276,
          "ymax": 576
        },
        "props": {
          "plate": [
            {
              "value": "nhk552",
              "score": 0.838
            }
          ],
          "region": [
            {
              "value": "gb",
              "score": 0.931
            }
          ]
        }
      },
      "vehicle": {
        "type": "Sedan",
        "score": 0.834,
        "box": {
          "xmin": 68,
          "ymin": 103,
          "xmax": 914,
          "ymax": 643
        },
        // Make Model, Orientation and Color are only available if you set mmc=true
        "props": {
          "make_model": [
            {
              "make": "Riley",
              "model": "RMF",
              "score": 0.339
            }
          ],
          "orientation": [
            {
              "value": "Front",
              "score": 0.939
            }
          ],
          "color": [
            {
              "value": "black",
              "score": 0.846
            }
          ]
        }
      },
      // Direction is only available is you set mmc=true and direction=true
      "direction": null,
      "direction_score": 0.0
    }
  ]
}

Each license plate has the following elements:

Attribute	Description
results/plate	Text of the license plate.
results/box	Bounding box for the license plate. Coordinates in pixels of the top-left and bottom-right corners of the plate.
results/dscore	Confidence level for plate detection. See below for more details.
results/score	Confidence level for reading the license plate text. See below for more details.
results/vehicle/type	Vehicle type: Big Truck, Bus, Motorcycle, Pickup Truck, Sedan, SUV, Van, Unknown.
results/vehicle/score	Confidence level for vehicle type prediction. If we cannot find a vehicle, the score is set to 0.
results/vehicle/box	Vehicle bounding box. If we cannot find a vehicle, the coordinates are all 0.
results/region/code	Region of license plate. Returns a code from the country list.
results/region/score	Confidence level for license plate region.
results/candidates	List of predictions for the license plate value. The first element is the top prediction (same as results/plate).
results/model_make/make	Prediction of vehicle make.
results/model_make/model	Prediction of vehicle model.
results/model_make/score	Confidence level for vehicle make and model prediction.
results/color/color	Vehicle color. One of black, blue, brown, green, red, silver, white, yellow, unknown.
results/color/score	Confidence level for vehicle color prediction.
results/orientation/orientation	Vehicle orientation. One of Front, Rear, Unknown.
results/orientation/score	Confidence level for vehicle orientation prediction.
results/direction	Vehicle direction of travel in degrees on the Unit Circle.
results/direction_score	Confidence level for vehicle's direction prediction.

Scores vary between 0 and 1. A prediction with a score close to 1 indicates high confidence.
The value dscore is the confidence level of the object detection. A score close to 1 indicates a high confidence. For example, if you don't want to miss any vehicles and you can tolerate some false positives, you can decide to use all results with a score above 0.3. However, if you want to avoid false positives and can tolerate missing a few vehicles, then discarding results below 0.7 is preferable. It depends on the use case and quality of the images you use.

info

View complete examples for ALPR API integration. Easily do batching and use the API on a video. Examples are written in multiple languages.

Error Responses

Engine Configuration

A lookup request can accept the parameter config. It is a JSON value to change the engine configuration. It can include the following values:

{"detection_rule":"strict"}: The license plates that are detected outside a vehicle will be discarded.
{"detection_mode":"vehicle"}: The default detection mode (plate) only returns vehicles if a license plate is also detected. To get vehicles without plates, use the value vehicle. See the response format.
{"region":"strict"}: Only accept the results that exactly match the templates of the specified region. For example, if the license plate of a region is 3 letters and 3 numbers, the value abc1234 will be discarded. For regions with vanity license plates (e.g. in us-ca), we do not recommend the use of Strict Mode. Otherwise, the engine will discard the vanity plates. A region must be specified in order for this parameter to work.
{"threshold_d":0.2, "threshold_o":0.6}: By default the engine will use those thresholds to filter the detection and OCR results. Anything below that will be discarded. You can set different values.
{"mode":"fast"}: The number of detection steps is always 1. On average it gives a 30% speed-up. May result in lower accuracy when using images with small vehicles.
{"mode":"redaction"}: Used for Plate Recognizer Blur. It includes more candidates during the plate detection step. This configuration will miss fewer plates but will increase the number of false positives (objects that are not license plates).
{"text_formats":["..."]}: List of regular expressions. They are used to guide the engine's predictions. For example, if you know the output is generally 3 digits and 2 letters, you would use - {"text_formats":["[0-9][0-9][0-9][a-z][a-z]"]}. More information about the format. The engine may not follow the format when the predictions are too different. If you want to exactly match the regexp, you should also use "region":"strict" (see above).
{"plates_per_vehicle":1}: Maximum number of license plates that a vehicle is expected to have.
{"zoom_in_vehicles":4}: Maximum number of vehicles Snapshot performs a zoom on to improve plate recognition. Increasing this parameter could help with high resolution images, but may have a negative effect on latency. New in version 1.47.0.

Examples

Here are a couple of examples of how to use the config parameter (with Shell or Python).

Shell
Python

#On Linux
#Custom threshold and fast mode:
curl -F "upload=@/path/to/car.jpg" \
  -F config="{\"mode\":\"fast\", \"threshold_d\":0.2, \"threshold_o\":0.6}" \
  -H "Authorization: Token YOUR_API_TOKEN" \
  https://api.platerecognizer.com/v1/plate-reader/

#Strict region matching:
curl -F "upload=@/path/to/car.jpg" \
  -F config="{\"region\":\"strict\"}" \
  -F region=us-ca \
  -H "Authorization: Token YOUR_API_TOKEN" \
  https://api.platerecognizer.com/v1/plate-reader/

#Prediction must include a vehicle:
curl -F "upload=@/path/to/car.jpg" \
  -F config="{\"detection_rule\":\"strict\"}" \
  -H "Authorization: Token YOUR_API_TOKEN" \
  https://api.platerecognizer.com/v1/plate-reader/

#On Windows
#Custom threshold and fast mode:
curl -F "upload=@c:\path\to\car.jpg" ^
  -F config="{\"mode\":\"fast\", \"threshold_d\":0.2, \"threshold_o\":0.6}" ^
  -H "Authorization: Token YOUR_API_TOKEN" ^
  https://api.platerecognizer.com/v1/plate-reader/

#Strict region matching:
curl -F "upload=@c:\path\to\car.jpg" ^
  -F config="{\"region\":\"strict\"}" ^
  -F region=us-ca ^
  -H "Authorization: Token YOUR_API_TOKEN" ^
  https://api.platerecognizer.com/v1/plate-reader/

#Prediction must include a vehicle:
curl -F "upload=@c:\path\to\car.jpg" ^
  -F config="{\"detection_rule\":\"strict\"}" ^
  -H "Authorization: Token YOUR_API_TOKEN" ^
  https://api.platerecognizer.com/v1/plate-reader/

import json
with open('/path/to/car.jpg', 'rb') as fp:
    response = requests.post(
        'https://api.platerecognizer.com/v1/plate-reader/',
        data=dict(config=json.dumps(dict(region="strict"))),
        files=dict(upload=fp),
        headers={'Authorization': 'Token YOUR_API_TOKEN'})

Statistics

Get number of recognition calls done during the current month. This API endpoint is for Snapshot Cloud only. For Snapshot SDK, use the info API.

HTTP Request

GET https://api.platerecognizer.com/v1/statistics/

curl -H "Authorization: Token YOUR_API_TOKEN" \
  https://api.platerecognizer.com/v1/statistics/

JSON Response

{
  "usage": {
    "month": 1,
    "calls": 128,
    "year": 2019,
    "resets_on": "2019-01-14T00:00:00Z"
  },
  "total_calls": 2500
}

Response fields description:

Attribute	Description
calls	Number of API calls made during the current period.
month	Month of the current period.
year	Year of the current period.
resets_on	Date when the counter will reset.
total_calls	Maximum number of API calls you can make during the period. Need more? Upgrade.

Errors

Error Code	Meaning
403	Forbidden: you do not have enough credits to perform this request or your API Token is wrong.
413	Payload Too Large response status code indicates that the request entity is larger than limits defined by our server. See upload limits.
429	Indicates the user has sent too many requests in a given amount of time. The Free Trial Snapshot API Cloud Plan has a limit of 1 lookup per second. A Snapshot API Cloud Subscription has a limit of 8 lookups per second. The Snapshot SDK does not have any lookup limits per second. Subscribe for a higher number of calls per second for your API Cloud plan. The response is `{"detail":"Request was throttled. Expected available in 1 second.","status_code":429}`.

Snapshot On-Premise API

Our service is also available on-premises. Get started with the SDK. It has a similar interface as the recognition API and it is hosted locally. See differences below.

info

Are you using the on-premise API from a different device? Make sure that your firewall allows it. For example, you can disable the Windows Defender firewall to check if it is blocking the API calls.

Recognition API

HTTP Request

POST http://localhost:8080/v1/plate-reader/

The CORS policy of this endpoint allows requests from all origins. This endpoint has no maximum calls per second contrary to our Cloud API.

Parameters

All the parameters from recognition API.

Linux
Windows

#On Linux
#Calling the API with just the image
curl -o car.jpg https://app.platerecognizer.com/static/demo.jpg ## Get an image
curl -F "[email protected]" \
  http://localhost:8080/v1/plate-reader/

#Sending the image in base64
curl -F "upload=$(base64 'image.jpg')" http://localhost:8080/v1/plate-reader/

#Calling with API with optional parameters config and mmc
#The region is set to Mexico and California
curl -F "upload=@/path/to/car.jpg" \
  -F regions=`mx` \
  -F regions=us-ca \
  -F mmc=true \
  -F config="{\"mode\":\"fast\"}" \
  http://localhost:8080/v1/plate-reader/

#On Windows
#Calling the API with just the image
curl -o car.jpg https://app.platerecognizer.com/static/demo.jpg
curl -F "[email protected]" ^
  http://localhost:8080/v1/plate-reader/

#Calling with API with optional parameters config and mmc
#The region is set to Mexico and California
curl -F "upload=@c:\path\to\car.jpg" ^
  -F regions=`mx` ^
  -F regions=us-ca ^
  -F mmc=true ^
  -F config="{\"mode\":\"fast\"}" ^
  http://localhost:8080/v1/plate-reader/

JSON Response

{
  "usage": {
    "max_calls": 1000,
    "calls": 44
  },
  "results": [
    // Same as cloud API example above.
  ],
  "camera_id": "null",
  "timestamp": "2020-01-16 17:00:00",
  "filename": "car.jpg"
}

SDK Version

Show version, webhooks and usage information.

HTTP Request

GET http://localhost:8080/info/

JSON Response

Returns the SDK version, license key and webhooks.

{
  "version": "1.3.8",
  "license_key": "XXX",
  "total_calls": 2500,
  "usage": {"calls": 10},
  "webhooks": []
}

WebHooks

Our service also supports webhooks. It allows you to receive a HTTP POST request to a target URL of your choosing. Go to webhooks settings page to manage your webhooks or add a new webhook target.

The target_url should return a valid HTTP status code (200). If the target_url consistently returns an error code, the hook will be removed and an email will be sent to the account owner.
To quickly test out this feature, you can use http://webhook.site. It generates a unique target URL and displays all the requests made to that URL.
A webhook is sent for each call to the recognition API even when no license plate is found.

Example of POST payload

{
  "hook": {
    "target": "http://localhost:8081/",
    "id": 2,
    "event": "image.done"
  },
  "data": {
    "processing_time": 0.186,
    "timestamp": "2019-08-31T14:22:06.983Z",
    "results": [
      {
        "box": {
          "xmin": 563,
          "ymin": 530,
          "ymax": 579,
          "xmax": 702
        },
        "plate": "765410",
        "score": 0.9131534678711563,
        "dscore": 0.4084282568529709
      },
      {
        "box": {
          "xmin": 563,
          "ymin": 530,
          "ymax": 579,
          "xmax": 702
        },
        "plate": "830265",
        "score": 0.7700640306685624,
        "dscore": 0.8493143507578083
      }
    ],
    "filename": "14_22_test.jpeg",
    "version": 1,
    "camera_id": null
  }
}

Data Only Webhook

Snapshot: HTTP Request

POST target_url

The request body contains the payload above in JSON format.

Webhook With Image

Snapshot: HTTP Request

POST target_url

The request body contains a multipart/form-data content. Receiving this data is like receiving the content of a form with an input of type file. It has two fields:

upload contains the image binary content
json is the JSON encoded data. See the example of the payload above.

info

The bounding box of the license plate are calculated based on the image sent by webhook.

Receiving Webhook Data

Do you need help creating the webhook receiver? Get started with our examples.

Detection Zones

Detection Zones exclude overlay texts, street signs or other objects.

Countries

Check the countries codes for regions parameter.

Snapshot Cloud API​

Authentication​

Read Number Plates from an Image​

HTTP Request​

POST Parameters​

Response​

Engine Configuration​

Examples​

Statistics​

HTTP Request​

JSON Response​

Errors​

Snapshot On-Premise API​

Recognition API​

HTTP Request​

Parameters​

JSON Response​

SDK Version​

HTTP Request​

JSON Response​

WebHooks​

Example of POST payload​

Data Only Webhook​

Snapshot: HTTP Request​

Webhook With Image​

Snapshot: HTTP Request​

Receiving Webhook Data​

Detection Zones​

Countries​

Snapshot Cloud API

Authentication

Read Number Plates from an Image

HTTP Request

POST Parameters

Response

Engine Configuration

Examples

Statistics

HTTP Request

JSON Response

Errors

Snapshot On-Premise API

Recognition API

HTTP Request

Parameters

JSON Response

SDK Version

HTTP Request

JSON Response

WebHooks

Example of POST payload

Data Only Webhook

Snapshot: HTTP Request

Webhook With Image

Snapshot: HTTP Request

Receiving Webhook Data

Detection Zones

Countries