Reference

PDF to HTML Node.js Reference

Node.js SDK

This reference describes the Node.js SDK's calling conventions, errors, helpers, and client methods for the PDF to HTML API. See the installation instructions for setup and the guide for usage examples.

SDK behavior

Calling conventions and results

Conversion methods such as convertUrl() and convertUrlToFile() support Promises and callbacks in Node.js SDK 7 and later. Omitting the callback argument or passing undefined returns a Promise. Handle it with await or .then()/.catch(). Supplying a valid callback selects callback mode and returns undefined.

Promise results

MethodsResultWhen it resolves
Content methods Buffer All HTML output has been received.
*ToFile Supplied file path The output has been written and the file closed.
*ToStream (Promise-only) Readable The response is available. Await a pipeline or finish async iteration to receive all output and observe later failures.

For HTML output, decode the Buffer with buffer.toString('utf8'). If isZippedOutput() returns true, save and extract the ZIP archive instead.

The SDK has no cancellation API. Closing a local stream does not guarantee that a conversion running on the service stops.

Callbacks

Content methods accept a callbacks object with required data and error handlers and an optional end handler:

HandlerMeaning
data(readStream) Receives the response stream.
error(message, statusCode, cause) Reports conversion failure. Status and underlying cause may be absent.
end() The conversion response is complete. Wait separately for your destination to finish writing.

File methods accept callback(error, filePath): success calls callback(null, filePath) after the file closes; failure passes the SDK error. Callback helpers can write a file or send an HTTP response.

Errors

  • Promise mode: conversion failures and invalid inputs reject the Promise.
  • Stream output: handle both Promise rejection and errors while consuming the stream.
  • Synchronous errors: an invalid callback argument, including null, throws TypeError. Constructors and setters remain synchronous; callback mode retains synchronous validation errors.

Conversion failures use pdfcrowd.Pdfcrowd.Error, a native Error subclass. Its cause holds an underlying error when available. See error details for status, reason, and message accessors.

Error object

pdfcrowd.Pdfcrowd.Error extends the native Error class. Its cause holds an underlying error when available. The table lists the SDK error object's methods and string representation.

OperationReturn typeDescription
getStatusCode number | undefined The HTTP status code, or undefined when unavailable.
getReasonCode number The PDFCrowd reason code, or -1 when unavailable.
getMessage string The error message.
toString string The complete error text, including status and reason codes and a documentation link when present.

Callback helpers

These functions return a callbacks object for content conversion methods.

pdfcrowd.saveToFile(filePath, callback)

Writes the conversion output to a file.

Callback:
The optional callback(error, filePath) reports failure or completion after the file closes.

pdfcrowd.sendGenericHttpResponse(response, contentType, fileName, disposition)

Sends the output in an HTTP response with the supplied content type and filename.

Defaults:
Optional disposition defaults to 'attachment'; use 'inline' to display the output in the browser.
Errors:
Conversion errors are sent as plain text in the HTTP response.
Availability: API client version >= 5.4.0

class PdfToHtmlClient

All setter methods return PdfToHtmlClient object unless specified otherwise.

Constructor

function PdfToHtmlClient(userName, apiKey)

Constructor for the PDFCrowd API client. Initialize a new instance of the conversion client with your PDFCrowd account credentials.

You must provide both your username and API key. This establishes the authenticated connection for all subsequent conversion operations.

TypeScript:
constructor(userName: string, apiKey: string);
Parameters:
  • userName - Your username at PDFCrowd.
  • apiKey - Your API key.

Conversion Input

convertUrl

Convert a PDF from a URL.

Use this as the primary method for converting web content, online documents, or any publicly accessible URL to the desired output format. Returns the conversion result as a byte array for further processing or direct use.

Promise:
client.convertUrl(url)
Callback:
client.convertUrl(url, callbacks)
TypeScript:
convertUrl(url: string, callbacks?: undefined): Promise<Buffer>;
convertUrl(url: string, callbacks: Callbacks): void;
Parameters:
  • url - The address of the PDF to convert.
    Constraint:
    • Supported protocols are http:// and https://.
  • callbacks - For callback mode; see Calling conventions and results.
Returns:
Promise<Buffer> - The complete conversion output. See Calling conventions and results.

convertUrlToStream

Run the conversion and return its output as a readable stream.

Promise:
client.convertUrlToStream(url)
TypeScript:
convertUrlToStream(url: string): Promise<Readable>;
Parameter:
  • url - The address of the PDF to convert.
    Constraint:
    • Supported protocols are http:// and https://.
Returns:
Promise<Readable> - The readable conversion output. See Calling conventions and results.

convertUrlToFile

Convert a PDF from a URL and save the conversion result directly to a local file.

Use this for simple file-based workflows, batch processing, or when you need to persist conversion output to disk.

Promise:
client.convertUrlToFile(url, filePath)
Callback:
client.convertUrlToFile(url, filePath, callback)
TypeScript:
convertUrlToFile(url: string, filePath: string, callback?: undefined): Promise<string>;
convertUrlToFile(url: string, filePath: string, callback: FileCallback): void;
Parameters:
  • url - The address of the PDF to convert.
    Constraint:
    • Supported protocols are http:// and https://.
  • filePath - The output file path.
    Constraint:
    • The converter generates an HTML or ZIP file. If ZIP file is generated, the file path must have a ZIP or zip extension.
  • callback - For callback mode; see Calling conventions and results.
Returns:
Promise<string> - The supplied output file path. See Calling conventions and results.

convertFile

Convert a local file to the desired output format.

Use this for processing files already on your system, converting uploaded documents, or batch processing local content. Returns the conversion result as a byte array for in-memory processing.

Promise:
client.convertFile(file)
Callback:
client.convertFile(file, callbacks)
TypeScript:
convertFile(file: string, callbacks?: undefined): Promise<Buffer>;
convertFile(file: string, callbacks: Callbacks): void;
Parameters:
  • file - The path to a local file to convert.
    Constraint:
    • The file must exist and not be empty.
  • callbacks - For callback mode; see Calling conventions and results.
Returns:
Promise<Buffer> - The complete conversion output. See Calling conventions and results.

convertFileToStream

Run the conversion and return its output as a readable stream.

Promise:
client.convertFileToStream(file)
TypeScript:
convertFileToStream(file: string): Promise<Readable>;
Parameter:
  • file - The path to a local file to convert.
    Constraint:
    • The file must exist and not be empty.
Returns:
Promise<Readable> - The readable conversion output. See Calling conventions and results.

convertFileToFile

Convert a local file and save the conversion result to another local file.

Use this for file-based batch processing, document transformation workflows, or when both input and output are file-based.

Promise:
client.convertFileToFile(file, filePath)
Callback:
client.convertFileToFile(file, filePath, callback)
TypeScript:
convertFileToFile(file: string, filePath: string, callback?: undefined): Promise<string>;
convertFileToFile(file: string, filePath: string, callback: FileCallback): void;
Parameters:
  • file - The path to a local file to convert.
    Constraint:
    • The file must exist and not be empty.
  • filePath - The output file path.
    Constraint:
    • The converter generates an HTML or ZIP file. If ZIP file is generated, the file path must have a ZIP or zip extension.
  • callback - For callback mode; see Calling conventions and results.
Returns:
Promise<string> - The supplied output file path. See Calling conventions and results.

convertRawData

Convert raw binary data to the desired output format.

Use this for processing binary content, handling file uploads as byte arrays, or when working with data from external APIs. Provides maximum flexibility for binary data conversions.

Promise:
client.convertRawData(data)
Callback:
client.convertRawData(data, callbacks)
TypeScript:
convertRawData(data: Buffer | string, callbacks?: undefined): Promise<Buffer>;
convertRawData(data: Buffer | string, callbacks: Callbacks): void;
Parameters:
Returns:
Promise<Buffer> - The complete conversion output. See Calling conventions and results.

convertRawDataToStream

Run the conversion and return its output as a readable stream.

Promise:
client.convertRawDataToStream(data)
TypeScript:
convertRawDataToStream(data: Buffer | string): Promise<Readable>;
Parameter:
  • data (Buffer | string) - The raw content to be converted.
Returns:
Promise<Readable> - The readable conversion output. See Calling conventions and results.

convertRawDataToFile

Convert raw binary data and save the conversion result to a local file.

Use this for processing binary uploads and persisting the output, handling data from external sources, or when working with byte array inputs that need file-based storage.

Promise:
client.convertRawDataToFile(data, filePath)
Callback:
client.convertRawDataToFile(data, filePath, callback)
TypeScript:
convertRawDataToFile(data: Buffer | string, filePath: string, callback?: undefined): Promise<string>;
convertRawDataToFile(data: Buffer | string, filePath: string, callback: FileCallback): void;
Parameters:
  • data (Buffer | string) - The raw content to be converted.
  • filePath - The output file path.
    Constraint:
    • The converter generates an HTML or ZIP file. If ZIP file is generated, the file path must have a ZIP or zip extension.
  • callback - For callback mode; see Calling conventions and results.
Returns:
Promise<string> - The supplied output file path. See Calling conventions and results.

convertStream

Convert content from an input stream to the desired output format.

Use this when integrating with I/O pipelines, processing data from network streams or file handles, or when the source data is provided as a stream by your application.

The input stream is buffered in memory before upload.

Promise:
client.convertStream(inStream)
Callback:
client.convertStream(inStream, callbacks)
TypeScript:
convertStream(inStream: Readable, callbacks?: undefined): Promise<Buffer>;
convertStream(inStream: Readable, callbacks: Callbacks): void;
Parameters:
Returns:
Promise<Buffer> - The complete conversion output. See Calling conventions and results.

convertStreamToStream

Run the conversion and return its output as a readable stream.

The input stream is buffered in memory before upload.

Promise:
client.convertStreamToStream(inStream)
TypeScript:
convertStreamToStream(inStream: Readable): Promise<Readable>;
Parameter:
  • inStream (Readable) - The input stream with source data.
Returns:
Promise<Readable> - The readable conversion output. See Calling conventions and results.

convertStreamToFile

Convert content from an input stream and save the conversion result to a local file.

Use this when processing streaming uploads that need to be saved, handling network data sources with file-based output, or building services that accept stream input and produce file output.

The input stream is buffered in memory before upload.

Promise:
client.convertStreamToFile(inStream, filePath)
Callback:
client.convertStreamToFile(inStream, filePath, callback)
TypeScript:
convertStreamToFile(inStream: Readable, filePath: string, callback?: undefined): Promise<string>;
convertStreamToFile(inStream: Readable, filePath: string, callback: FileCallback): void;
Parameters:
  • inStream (Readable) - The input stream with source data.
  • filePath - The output file path.
    Constraint:
    • The converter generates an HTML or ZIP file. If ZIP file is generated, the file path must have a ZIP or zip extension.
  • callback - For callback mode; see Calling conventions and results.
Returns:
Promise<string> - The supplied output file path. See Calling conventions and results.

General Options

function setPdfPassword(password)

Password to open the encrypted PDF file.

TypeScript:
setPdfPassword(password: string): this;
Parameter:
  • password - The input PDF password.

function setScaleFactor(factor)

Set the scaling factor (zoom) for the main page area.

TypeScript:
setScaleFactor(factor: number): this;
Parameter:
  • factor (number) - The percentage value.
    Constraint:
    • Must be a positive integer.
    Default:
    100

function setPrintPageRange(pages)

Set the page range to print.

TypeScript:
setPrintPageRange(pages: string): this;
Parameter:
  • pages
    Constraint:
    • A comma separated list of page numbers or ranges.
Examples:
  • Just the second page is printed: setPrintPageRange("2")
  • The first and the third page are printed: setPrintPageRange("1,3")
  • Everything except the first page is printed: setPrintPageRange("2-")
  • Just first 3 pages are printed: setPrintPageRange("-3")
  • Pages 3, 6, 7, 8 and 9 are printed: setPrintPageRange("3,6-9")

function setDpi(dpi)

Set the output graphics DPI. Higher values (144-300) improve quality but increase file size. Use 144 for web, 300 for print.

TypeScript:
setDpi(dpi: number): this;
Availability:
API client >= 5.16.0, converter >= 20.10. See versioning.
Parameter:
  • dpi (number) - The DPI value.
    Default:
    144

function setImageMode(mode)

Specify where the images are stored. Use separate files for better performance with large images or when serving images from a CDN. Use embedded for single-file portability.

TypeScript:
setImageMode(mode: string): this;
Parameter:
  • mode - The image storage mode.
    Allowed Values:
    • embed — The images are embedded into the output HTML file.
    • separate — The images are saved to separate files. In this mode the output of the conversion is a zip file containing the HTML and all image files.
    • none — The images are ignored and not converted.
    Default:
    embed

function setImageFormat(imageFormat)

Specify the format for the output images. Use PNG for lossless quality, JPG for smaller file sizes, or SVG for vector graphics.

TypeScript:
setImageFormat(imageFormat: string): this;
Availability:
API client >= 5.17.0, converter >= 20.10. See versioning.
Parameter:
  • imageFormat - The image format.
    Allowed Values:
    • png
    • jpg
    • svg
    Default:
    png

function setCssMode(mode)

Specify where the style sheets are stored. Use separate files for better browser caching and easier debugging. Use embedded for single-file HTML output.

TypeScript:
setCssMode(mode: string): this;
Parameter:
  • mode - The style sheet storage mode.
    Allowed Values:
    • embed — Style sheets are embedded into the output HTML file.
    • separate — Style sheets are saved to separate files. In this mode the output of the conversion is a zip file containing the HTML and all style sheets.
    Default:
    embed

function setFontMode(mode)

Specify where the fonts are stored. Use separate files for better browser caching and to reduce HTML file size. Use embedded for single-file portability.

TypeScript:
setFontMode(mode: string): this;
Parameter:
  • mode - The font storage mode.
    Allowed Values:
    • embed — The fonts are embedded into the output HTML file.
    • separate — The font are saved to separate files. In this mode the output of the conversion is a zip file containing HTML and all font files.
    Default:
    embed

function setType3Mode(mode)

Set the processing mode for handling Type 3 fonts.

TypeScript:
setType3Mode(mode: string): this;
Availability:
API client >= 6.2.0, converter >= 24.04. See versioning.
Parameter:
  • mode - The type3 font mode.
    Allowed Values:
    • raster — Rasters Type 3 fonts into images, ensuring an exact visual representation in the HTML output.
    • convert — Attempts to convert Type 3 fonts to a web font, resulting in smaller file sizes with some possible visual discrepancies.
    Default:
    raster

function setSplitLigatures(value)

Converts ligatures, two or more letters combined into a single glyph, back into their individual ASCII characters.

TypeScript:
setSplitLigatures(value: boolean): this;
Parameter:
  • value (boolean) - Set to true to split ligatures.
    Default:
    false

function setCustomCss(css)

Apply custom CSS to the output HTML document to modify the visual appearance and layout. Use this to customize the styling of the converted HTML, adjust fonts, colors, spacing, or override default conversion styles.

Use !important in your CSS rules to prioritize and override conflicting styles.

TypeScript:
setCustomCss(css: string): this;
Availability:
API client >= 6.2.0, converter >= 24.04. See versioning.
Parameter:
  • css - A string containing valid CSS.
Example:
  • Set the main background color to azure: setCustomCss("#page-container { background-color: azure; }")

function setHtmlNamespace(prefix)

Add the specified prefix to all id and class attributes in the HTML content, creating a namespace for safe integration into another HTML document. This ensures unique identifiers, preventing conflicts when merging with other HTML.

TypeScript:
setHtmlNamespace(prefix: string): this;
Availability:
API client >= 6.3.0, converter >= 24.04. See versioning.
Parameter:
  • prefix - The prefix to add before each id and class attribute name.
    Constraint:
    • Start with a letter or underscore, and use only letters, numbers, hyphens, underscores, or colons.
Examples:
  • Namespace for first PDF embed: setHtmlNamespace("pdf1_")
  • Custom namespace to avoid conflicts: setHtmlNamespace("uniqueID123_")

function isZippedOutput() { return bool; }

A helper method to determine if the output file is a zip archive. The output of the conversion may be either an HTML file or a zip file containing the HTML and its external assets.

TypeScript:
isZippedOutput(): boolean;
Returns:
bool - True if the conversion output is a zip file, otherwise False.

function setForceZip(value)

Enforce the zip output format. Use when you want output as a zip archive even if single-file output would be possible.

TypeScript:
setForceZip(value: boolean): this;
Parameter:
  • value (boolean) - Set to true to get the output as a zip archive.
    Default:
    false

function setTitle(title)

Set the HTML title. The title from the input PDF is used by default.

TypeScript:
setTitle(title: string): this;
Parameter:
  • title - The HTML title.

function setSubject(subject)

Set the HTML subject. The subject from the input PDF is used by default.

TypeScript:
setSubject(subject: string): this;
Parameter:
  • subject - The HTML subject.

function setAuthor(author)

Set the HTML author. The author from the input PDF is used by default.

TypeScript:
setAuthor(author: string): this;
Parameter:
  • author - The HTML author.

function setKeywords(keywords)

Associate keywords with the HTML document. Keywords from the input PDF are used by default.

TypeScript:
setKeywords(keywords: string): this;
Parameter:
  • keywords - The string containing the keywords.

Miscellaneous

function setDebugLog(value)

Turn on debug logging to troubleshoot conversion issues. Details about the conversion process, including resource loading, rendering steps, and error messages are stored in the debug log. Use this when conversions fail or produce unexpected results. The URL of the log can be obtained from the getDebugLogUrl method or available in conversion statistics.

TypeScript:
setDebugLog(value: boolean): this;
Parameter:
  • value (boolean) - Set to true to enable debug logging.
    Default:
    false

function getDebugLogUrl() { return string; }

Get the URL of the debug log for the last conversion.

TypeScript:
getDebugLogUrl(): string | null;
Returns:
string - The link to the debug log.

function getRemainingCreditCount() { return int; }

Get the number of conversion credits available in your account. Use this to monitor your credit usage and implement alerts before running out of credits.
This method can only be called after a call to one of the convertXtoY methods.
The returned value can differ from the actual count if you run parallel conversions.
The special value 999999 is returned if the information is not available.

TypeScript:
getRemainingCreditCount(): number;
Returns:
int - The number of credits.

function getConsumedCreditCount() { return int; }

Get the number of credits consumed by the last conversion. Use this to track costs per conversion, especially for complex documents or operations that may consume multiple credits.

TypeScript:
getConsumedCreditCount(): number;
Returns:
int - The number of credits.

function getJobId() { return string; }

Get the unique job ID for the conversion. Use this to track conversions in your logs, correlate with debug logs, or reference specific conversions when contacting support.

TypeScript:
getJobId(): string;
Returns:
string - The unique job identifier.

function getPageCount() { return int; }

Get the number of pages in the output document. Use this to validate conversion results, calculate pagination for user interfaces, or track document complexity metrics.

TypeScript:
getPageCount(): number;
Returns:
int - The page count.

function getOutputSize() { return int; }

Get the size of the output document in bytes. Use this to check file sizes before delivery, implement size-based quotas, or optimize storage allocation.

TypeScript:
getOutputSize(): number;
Returns:
int - The count of bytes.

function getVersion() { return string; }

Get the version details including API version, converter version, and client library version. Use this for debugging, logging, or ensuring compatibility when reporting issues.

TypeScript:
getVersion(): string;
Returns:
string - API version, converter version, and client version.

function setTag(tag)

Tag the conversion with a custom value for tracking and analytics. Use this to categorize conversions by customer ID, document type, or business unit. The tag appears in conversion statistics. A value longer than 32 characters is cut off.

TypeScript:
setTag(tag: string): this;
Parameter:
  • tag - A string with the custom tag.
Example:
  • Track job in analytics: setTag("client-1234")

function setHttpProxy(proxy)

A proxy server used by the conversion process for accessing the source URLs with HTTP scheme. This can help circumvent regional restrictions or provide limited access to your intranet.

TypeScript:
setHttpProxy(proxy: string): this;
Parameter:
  • proxy
    Constraint:
    • The value must have format DOMAIN_OR_IP_ADDRESS:PORT.
Examples:
  • Corporate proxy server: setHttpProxy("myproxy.com:8080")
  • Direct IP proxy connection: setHttpProxy("113.25.84.10:33333")

function setHttpsProxy(proxy)

A proxy server used by the conversion process for accessing the source URLs with HTTPS scheme. This can help circumvent regional restrictions or provide limited access to your intranet.

TypeScript:
setHttpsProxy(proxy: string): this;
Parameter:
  • proxy
    Constraint:
    • The value must have format DOMAIN_OR_IP_ADDRESS:PORT.
Examples:
  • Secure proxy for HTTPS: setHttpsProxy("myproxy.com:443")
  • Direct secure proxy IP: setHttpsProxy("113.25.84.10:44333")

API Client Options

function setConverterVersion(version)

Set the converter version. Different versions may produce different output. Choose which one provides the best output for your case.

TypeScript:
setConverterVersion(version: string): this;
Availability:
API client >= 5.0.0. See versioning.
Parameter:
  • version - The version identifier.
    Allowed Values:
    • 24.04 — Version 24.04.
    • 20.10 — Version 20.10.
    • 18.10 — Version 18.10.
    • latest — Version 20.10 is used.
    Default:
    24.04

function setUseHttp(value)

Specify whether to use HTTP or HTTPS when connecting to the PDFCrowd API.

TypeScript:
setUseHttp(value: boolean): this;
Parameter:
  • value (boolean) - Set to true to use HTTP.
    Default:
    false

function setClientUserAgent(agent)

Specify the User-Agent HTTP header that the client library will use when interacting with the API.

TypeScript:
setClientUserAgent(agent: string): this;
Availability:
API client >= 6.4.0 See versioning.
Parameter:
  • agent - The user agent string.

function setProxy(host, port, userName, password)

Specify an HTTP proxy that the API client library will use to connect to the internet.

TypeScript:
setProxy(host: string, port: number, userName: string, password: string): this;
Parameters:
  • host - The proxy hostname.
  • port (number) - The proxy port.
  • userName - The username.
  • password - The password.

function setRetryCount(count)

Specify the number of automatic retries when a 502 or 503 HTTP status code is received. The status code indicates a temporary network issue. This feature can be disabled by setting to 0.

TypeScript:
setRetryCount(count: number): this;
Parameter:
  • count (number) - Number of retries.
    Default:
    1
Example:
  • Retry failed requests three times: setRetryCount(3)