Document Classifier

Detect the class of an incoming PDF, JPG, or PNG document using keyword rules or built-in AI, so you can route it to the right processing template.

Try it live: Document Classifier → API Tester — send a real request from your browser.

POST /v1/pdf/classifier

Document Classifier can automatically find class of input PDF, JPG, PNG document by analyzing its content using the built-in AI or custom defined classification rules.

The best way to develop, test and maintain classification rules is to use Classifier Tester Tool from PDF.co Document Classifier UI . Use this tool to quickly edit and test rules on single PDFs and on folders.

Attributes

Attributes are case-sensitive and should be inside JSON for POST request. for example: { "url": "https://example.com/file1.pdf" }

Attribute	Type	Required	Default	Description
url	string	Yes	-	URL to the source file url attribute
callback	string	No	-	The callback URL (or Webhook) used to receive the POST data. see Webhooks & Callbacks. This is only applicable when async is set to true.
httpusername	string	No	-	HTTP auth user name if required to access source URL.
httppassword	string	No	-	HTTP auth password if required to access source URL.
inline	boolean	No	false	Set to true to return results inside the response. Otherwise, the endpoint will return a URL to the output file generated.
password	string	No	-	Password for the PDF file.
async	boolean	No	false	Set async to true for long processes to run in the background, API will then return a jobId which you can use with the Background Job Check endpoint. Also see Webhooks & Callbacks
name	string	No	-	File name for the generated output, the input must be in string format.
expiration	integer	No	60	Set the expiration time for the output link in minutes. After this specified duration, any generated output file(s) will be automatically deleted from PDF.co Temporary Files Storage. The maximum duration for link expiration varies based on your current subscription plan. To store permanent input files (e.g. re-usable images, pdf templates, documents) consider using PDF.co Built-In Files Storage.
caseSensitive	boolean	No	true	Set to false to don’t use case-sensitive search.
rulescsv	string	No	-	Define custom classification rules in CSV format. See the rulescsv.
rulescsvurl	string	No	-	URL to the CSV file with classification rules. For the format, see the description above rulescsv parameter
profiles	object	No	-	See Profiles for more information.
RenderTextObjects	boolean	No	true	Render text objects or not
RenderVectorObjects	boolean	No	true	Render vector objects or not
RenderImageObjects	boolean	No	true	Render image objects or not
TIFFCompression	string	No	LZW	TIFF compression algorithm. The options are: None, LZW, CCITT3, CCITT4, RLE
OCRMode	string	No	Auto	Specifies how OCR (Optical Character Recognition) should process input content, offering various modes to tailor text extraction based on content type such as images, fonts, and vector graphics. For more information, see OCR Extraction Modes.
OCRResolution	integer	No	300	Use this parameter to change the OCR resolution from the default 300 dpi. The range is from 72 to 1200 dpi.
RotationAngle	integer	No	-	Use manual rotation to handle PDFs with vertically drawn text. Normally, OCR automatically detects page rotation in PDFs and extracts text accurately. However, in some cases, the PDF might not have an actual rotated page --- Rather, the text itself is drawn vertically. In such scenarios, auto-detection may fail. You can use this parameter to manually set the page rotation. The available angles are: 0, 1, 2, 3.
LineGroupingMode	string	No	None	Controls line grouping in PDF text extraction. Modes: None (no grouping), GroupByRows (merge rows if all cells align), GroupByColumns (merge cells by column), JoinOrphanedRows (merge single-cell rows to above if no separator).
ConsiderFontColors	boolean	No	false	Controls whether font colors should be considered when detecting table structure and merging text objects during PDF extraction. Set to true to consider font colors.
DetectNewColumnBySpacesRatio	string	No	1.2	Controls how spaces between words are interpreted for column detection in PDF text extraction. It defines the ratio of space width that determines when text should be treated as being in separate columns.
AutoAlignColumnsToHeader	boolean	No	true	Controls how columns are detected and aligned during table extraction from PDF documents. It affects both table structure detection and text extraction with formatting preservation. Set to true to automatically align columns to the header row. When set to true (default), the row with the most columns is used as the header, and all other rows are aligned to this structure --- ideal for well-structured tables. When set to false, columns are analyzed independently across all rows to build the structure, which works better for inconsistent or irregular tables.
OCRImagePreprocessingFilters.AddGammaCorrection()	array[string (float format)]	No	["1.4"]	Adds a gamma correction filter to the image preprocessing pipeline used during OCR (Optical Character Recognition). This filter adjusts the brightness and contrast of an image by applying a non-linear gamma correction to improve text recognition quality.
OCRImagePreprocessingFilters.AddGrayscale()	boolean	No	false	Set to true to preprocessing filter that converts a colored document/image to grayscale before performing OCR
OCRAutoModeMinExistingTextLength	integer	No	8	The minimum number of characters a page must have to skip OCR. If a page has fewer, OCR will run. For example, if set to 8, OCR is skipped on pages with more than 8 characters.
DataEncryptionAlgorithm	string	No	-	Controls the encryption algorithm used for data encryption. See User-Controlled Encryption for more information. The available algorithms are: AES128, AES192, AES256.
DataEncryptionKey	string	No	-	Controls the encryption key used for data encryption. See User-Controlled Encryption for more information.
DataEncryptionIV	string	No	-	Controls the encryption IV used for data encryption. See User-Controlled Encryption for more information.
DataDecryptionAlgorithm	string	No	-	Controls the decryption algorithm used for data decryption. See User-Controlled Encryption for more information. The available algorithms are: AES128, AES192, AES256.
DataDecryptionKey	string	No	-	Controls the decryption key used for data decryption. See User-Controlled Encryption for more information.
DataDecryptionIV	string	No	-	Controls the decryption IV used for data decryption. See User-Controlled Encryption for more information.

rulescsv

Rules are in CSV format where each row contains: class name, logic (AND or OR (default)), and keywords separated by a comma. Each row is separated by the \n symbol. You can use regular expressions for keywords with this syntax: /keyword or regexp/i where i is the case-insensitive flag. Please note that all \ symbols should add the prefix \ because of JSON format, so \d becomes \\d and so on.

Custom Rules Example 1 for rulescsv.

Amazon AWS, OR, Amazon Web Services Invoice, Amazon CloudFront\nDigital Ocean, OR,DigitalOcean, DOInvoice\nACME,OR, ACME Inc.,1540 Long Street

Custom Rules Example 2.

Medical Report,AND,/Instructing Party|Medical Report|Date Of Injury|Med Agency Ref/i\r\nInjured Claimant,OR, Injured Claimant, Injured Patient ID

Document Classifier Usage Guide

This Document Classifier checks content of input PDF, JPG, PNG, or TIFF. It uses AI to automatically determine the class of the document (e.g., finance, invoice) and returns the result to the user. Custom-defined classification rules can also be used.

Use this Document Classifier to quickly build a workflow for sorting input documents and PDF files.

How to Create and Test Custom Classification Rules

Classification rules are stored in CSV format, one line per class, with the following format:

className, logicType, keyword1, keyword2, keyword3 ...

Where:

• className – The name of the class. It will be returned if rules from this class match the document.
• logicType – (Optional) Logic to use for keywords. Can be OR (default) or AND. OR means the class is identified if one or more keywords match. AND means all keywords must match. If not specified, OR is assumed.
• keyword1, keyword2, keyword3 – Keywords or phrases to check. Can include regular expressions, e.g., /\d+/ or /Medical Report|Med Report/i.

Sample Rules

Invoice,OR,Invoice Number,Invoice #,Invoice No,Tax Invoice,,
Purchase Order,OR,PO Number,Order Number,Order No,,,
Bill,OR,Bill Date,Billing Period,Bill Number,,,
Bank Statement,OR,/Account Statement/i,/Statement of Account/i,Business Checking,Accounts Payable,/Statement No/i,
Income Statement,OR,/Income Statement/i,,,,,
Has US Number,OR,"/\b-?(\d+,?)+(\.\d\d)\b/",,,,,
Medical Report,AND,/Medical Report|Med Report/i

Query parameters

No query parameters accepted.

Responses

Parameter	Type	Description
body	object	Response body.
pageCount	integer	Number of pages in the PDF document.
error	boolean	Indicates whether an error occurred (false means success)
status	string	Status code of the request (200, 404, 500, etc.). For more information, see Response Codes.. For more information, see Response Codes.
credits	integer	Number of credits consumed by the request
remainingCredits	integer	Number of credits remaining in the account
duration	integer	Time taken for the operation in milliseconds

Example Payload

To see the request size limits, please refer to the Request Size Limits.

{
  "url": "https://pdfco-test-files.s3.us-west-2.amazonaws.com/document-parser/sample-invoice.pdf",
  "async": false,
  "inline": "true",
  "password": "",
  "profiles": ""
}

Example Response

To see the main response codes, please refer to the Response Codes page.

{
  "body": {
    "classes": [
      {
        "class": "invoice"
      },
      {
        "class": "finance"
      },
      {
        "class": "documents"
      }
    ]
  },
  "pageCount": 1,
  "error": false,
  "status": 200,
  "credits": 42,
  "duration": 353,
  "remainingCredits": 98019328
}

Inconsistent URL Encoding in cURL Output: When using cURL to make API requests, the output JSON may show URL characters encoded as Unicode escape sequences. For example, the ampersand character (&) may appear as \u0026 in the cURL output. This is normal JSON encoding behavior and does not affect the validity of the URL. The URL will function correctly when used, as JSON parsers automatically decode these escape sequences. If you’re parsing the response programmatically, your JSON parser will handle this conversion automatically.

Code Samples

CURL

curl --location --request POST 'https://api.pdf.co/v1/pdf/classifier' \
--header 'Content-Type: application/json' \
--header 'x-api-key: *******************' \
--data-raw '{
"url": "https://pdfco-test-files.s3.us-west-2.amazonaws.com/document-parser/sample-invoice.pdf",
"async": false,
"inline": "true",
"password": "",
"profiles": ""
} '

JavaScript/Node.js

var request = require('request');
  var options = {
    'method': 'POST',
    'url': 'https://api.pdf.co/v1/pdf/classifier',
    'headers': {
      'Content-Type': 'application/json',
      'x-api-key': 'YOUR_PDFCO_API_KEY'
    },
    body: JSON.stringify({
      "url": "https://pdfco-test-files.s3.us-west-2.amazonaws.com/document-parser/sample-invoice.pdf",
      "async": false,
      "encrypt": "false",
      "inline": "true",
      "password": "",
      "profiles": ""
    })

  };
  request(options, function (error, response) {
    if (error) throw new Error(error);
    console.log(response.body);
  });

C#

using System;
  using RestSharp;
  namespace HelloWorldApplication {
          class HelloWorld {
                  static void Main(string[] args) {
                          var client = new RestClient("https://api.pdf.co/v1/pdf/classifier");
                          client.Timeout = -1;
                          var request = new RestRequest(Method.POST);
                          request.AddHeader("Content-Type", "application/json");
                          request.AddHeader("x-api-key", "YOUR_PDFCO_API_KEY");
                          var body = @"{" + "\n" +
                          @"    ""url"": ""https://pdfco-test-files.s3.us-west-2.amazonaws.com/document-parser/sample-invoice.pdf""," + "\n" +
                          @"    ""async"": false," + "\n" +
                          @"    ""encrypt"": ""false""," + "\n" +
                          @"    ""inline"": ""true""," + "\n" +
                          @"    ""password"": """"," + "\n" +
                          @"    ""profiles"": """"" + "\n" +
                          @"} ";
                          request.AddParameter("application/json", body,  ParameterType.RequestBody);
                          IRestResponse response = client.Execute(request);
                          Console.WriteLine(response.Content);
                  }
          }
  }

Java

import java.io.*;
  import okhttp3.*;
  public class main {
          public static void main(String []args) throws IOException{
                  OkHttpClient client = new OkHttpClient().newBuilder()
                          .build();
                  MediaType mediaType = MediaType.parse("application/json");
                  RequestBody body = RequestBody.create(mediaType, "{\n    \"url\": \"https://pdfco-test-files.s3.us-west-2.amazonaws.com/document-parser/sample-invoice.pdf\",\n    \"async\": false,\n    \"encrypt\": \"false\",\n    \"inline\": \"true\",\n    \"password\": \"\",\n    \"profiles\": \"\"\n} ");
                  Request request = new Request.Builder()
                          .url("https://api.pdf.co/v1/pdf/classifier")
                          .method("POST", body)
                          .addHeader("Content-Type", "application/json")
                          .addHeader("x-api-key", "YOUR_PDFCO_API_KEY")
                          .build();
                  Response response = client.newCall(request).execute();
                  System.out.println(response.body().string());
          }
  }

PHP

<?php

      $curl = curl_init();

      curl_setopt_array($curl, array(
              CURLOPT_URL => 'https://api.pdf.co/v1/pdf/classifier',
              CURLOPT_RETURNTRANSFER => true,
              CURLOPT_ENCODING => '',
              CURLOPT_MAXREDIRS => 10,
              CURLOPT_TIMEOUT => 0,
              CURLOPT_FOLLOWLOCATION => true,
              CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
              CURLOPT_CUSTOMREQUEST => 'POST',
              CURLOPT_POSTFIELDS =>'{
          "url": "https://pdfco-test-files.s3.us-west-2.amazonaws.com/document-parser/sample-invoice.pdf",
          "async": false,
          "encrypt": "false",
          "inline": "true",
          "password": "",
          "profiles": ""
      } ',
              CURLOPT_HTTPHEADER => array(
                      'Content-Type: application/json',
                      'x-api-key: YOUR_PDFCO_API_KEY'
              ),
      ));

      $response = json_decode(curl_exec($curl));

      curl_close($curl);
      echo "<h2>Output:</h2><pre>", var_export($response, true), "</pre>";

  ?>