This page describes how to convert web pages and HTML to images in Golang using the Pdfcrowd API. The API is easy to use and the integration takes only a few of lines of code.
go get github.com/pdfcrowd/pdfcrowd-go
We also offer other installation options.
Authentication is needed in order to use the Pdfcrowd API. The credentials used for accessing the API are your Pdfcrowd username and the API key.
demo
ce544b6ea52a5621fb9d55f8b542d14d
To get your personal API credentials, you can start a free API trial or buy the API license.
Enter a web page or upload an HTML file to get an image preview and integration code that you can copy and paste to your application.
Or you can choose from the examples below and adapt the code to your needs. You can also interactively explore the API in the API Playground.
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // create the API client instance client := pdfcrowd.NewHtmlToImageClient("demo", "ce544b6ea52a5621fb9d55f8b542d14d") // configure the conversion client.SetOutputFormat("png") // run the conversion and write the result to a file err := client.ConvertUrlToFile("http://www.example.com", "example.png") // check for the conversion error handleError(err) } func handleError(err error) { if err != nil { // report the error why, ok := err.(pdfcrowd.Error) if ok { os.Stderr.WriteString(fmt.Sprintf("Pdfcrowd Error: %s\n", why)) } else { os.Stderr.WriteString(fmt.Sprintf("Generic Error: %s\n", err)) } // rethrow or handle the exception panic(err.Error()) } }
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // create the API client instance client := pdfcrowd.NewHtmlToImageClient("demo", "ce544b6ea52a5621fb9d55f8b542d14d") // configure the conversion client.SetOutputFormat("png") // run the conversion and store the result into the "image" variable image, err := client.ConvertUrl("http://www.example.com") // check for the conversion error handleError(err) // at this point the "image" variable contains PNG raw data and // can be sent in an HTTP response, saved to a file, etc. } func handleError(err error) { if err != nil { // report the error why, ok := err.(pdfcrowd.Error) if ok { os.Stderr.WriteString(fmt.Sprintf("Pdfcrowd Error: %s\n", why)) } else { os.Stderr.WriteString(fmt.Sprintf("Generic Error: %s\n", err)) } // rethrow or handle the exception panic(err.Error()) } }
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // create the API client instance client := pdfcrowd.NewHtmlToImageClient("demo", "ce544b6ea52a5621fb9d55f8b542d14d") // configure the conversion client.SetOutputFormat("png") // create an output stream for the conversion result outputStream, err := os.Create("example.png") // check for a file creation error handleError(err) // close the output stream defer outputStream.Close() // run the conversion and write the result into the output stream err = client.ConvertUrlToStream("http://www.example.com", outputStream) // check for the conversion error handleError(err) } func handleError(err error) { if err != nil { // report the error why, ok := err.(pdfcrowd.Error) if ok { os.Stderr.WriteString(fmt.Sprintf("Pdfcrowd Error: %s\n", why)) } else { os.Stderr.WriteString(fmt.Sprintf("Generic Error: %s\n", err)) } // rethrow or handle the exception panic(err.Error()) } }
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // create the API client instance client := pdfcrowd.NewHtmlToImageClient("demo", "ce544b6ea52a5621fb9d55f8b542d14d") // configure the conversion client.SetOutputFormat("png") // run the conversion and write the result to a file err := client.ConvertFileToFile("/path/to/MyLayout.html", "MyLayout.png") // check for the conversion error handleError(err) } func handleError(err error) { if err != nil { // report the error why, ok := err.(pdfcrowd.Error) if ok { os.Stderr.WriteString(fmt.Sprintf("Pdfcrowd Error: %s\n", why)) } else { os.Stderr.WriteString(fmt.Sprintf("Generic Error: %s\n", err)) } // rethrow or handle the exception panic(err.Error()) } }
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // create the API client instance client := pdfcrowd.NewHtmlToImageClient("demo", "ce544b6ea52a5621fb9d55f8b542d14d") // configure the conversion client.SetOutputFormat("png") // run the conversion and store the result into the "image" variable image, err := client.ConvertFile("/path/to/MyLayout.html") // check for the conversion error handleError(err) // at this point the "image" variable contains PNG raw data and // can be sent in an HTTP response, saved to a file, etc. } func handleError(err error) { if err != nil { // report the error why, ok := err.(pdfcrowd.Error) if ok { os.Stderr.WriteString(fmt.Sprintf("Pdfcrowd Error: %s\n", why)) } else { os.Stderr.WriteString(fmt.Sprintf("Generic Error: %s\n", err)) } // rethrow or handle the exception panic(err.Error()) } }
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // create the API client instance client := pdfcrowd.NewHtmlToImageClient("demo", "ce544b6ea52a5621fb9d55f8b542d14d") // configure the conversion client.SetOutputFormat("png") // create an output stream for the conversion result outputStream, err := os.Create("MyLayout.png") // check for a file creation error handleError(err) // close the output stream defer outputStream.Close() // run the conversion and write the result into the output stream err = client.ConvertFileToStream("/path/to/MyLayout.html", outputStream) // check for the conversion error handleError(err) } func handleError(err error) { if err != nil { // report the error why, ok := err.(pdfcrowd.Error) if ok { os.Stderr.WriteString(fmt.Sprintf("Pdfcrowd Error: %s\n", why)) } else { os.Stderr.WriteString(fmt.Sprintf("Generic Error: %s\n", err)) } // rethrow or handle the exception panic(err.Error()) } }
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // create the API client instance client := pdfcrowd.NewHtmlToImageClient("demo", "ce544b6ea52a5621fb9d55f8b542d14d") // configure the conversion client.SetOutputFormat("png") // run the conversion and write the result to a file err := client.ConvertStringToFile("<html><body><h1>Hello World!</h1></body></html>", "HelloWorld.png") // check for the conversion error handleError(err) } func handleError(err error) { if err != nil { // report the error why, ok := err.(pdfcrowd.Error) if ok { os.Stderr.WriteString(fmt.Sprintf("Pdfcrowd Error: %s\n", why)) } else { os.Stderr.WriteString(fmt.Sprintf("Generic Error: %s\n", err)) } // rethrow or handle the exception panic(err.Error()) } }
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // create the API client instance client := pdfcrowd.NewHtmlToImageClient("demo", "ce544b6ea52a5621fb9d55f8b542d14d") // configure the conversion client.SetOutputFormat("png") // run the conversion and store the result into the "image" variable image, err := client.ConvertString("<html><body><h1>Hello World!</h1></body></html>") // check for the conversion error handleError(err) // at this point the "image" variable contains PNG raw data and // can be sent in an HTTP response, saved to a file, etc. } func handleError(err error) { if err != nil { // report the error why, ok := err.(pdfcrowd.Error) if ok { os.Stderr.WriteString(fmt.Sprintf("Pdfcrowd Error: %s\n", why)) } else { os.Stderr.WriteString(fmt.Sprintf("Generic Error: %s\n", err)) } // rethrow or handle the exception panic(err.Error()) } }
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // create the API client instance client := pdfcrowd.NewHtmlToImageClient("demo", "ce544b6ea52a5621fb9d55f8b542d14d") // configure the conversion client.SetOutputFormat("png") // create an output stream for the conversion result outputStream, err := os.Create("HelloWorld.png") // check for a file creation error handleError(err) // close the output stream defer outputStream.Close() // run the conversion and write the result into the output stream err = client.ConvertStringToStream("<html><body><h1>Hello World!</h1></body></html>", outputStream) // check for the conversion error handleError(err) } func handleError(err error) { if err != nil { // report the error why, ok := err.(pdfcrowd.Error) if ok { os.Stderr.WriteString(fmt.Sprintf("Pdfcrowd Error: %s\n", why)) } else { os.Stderr.WriteString(fmt.Sprintf("Generic Error: %s\n", err)) } // rethrow or handle the exception panic(err.Error()) } }
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // create the API client instance client := pdfcrowd.NewHtmlToImageClient("demo", "ce544b6ea52a5621fb9d55f8b542d14d") // configure the conversion client.SetOutputFormat("png") client.SetDebugLog(true) // run the conversion and write the result to a file err := client.ConvertFileToFile("/path/to/MyLayout.html", "MyLayout.png") // check for the conversion error handleError(err) // print URL to the debug log fmt.Println("Debug log url:", client.GetDebugLogUrl()) // print the number of available conversion credits in your account fmt.Println("Remaining credit count:", client.GetRemainingCreditCount()) // print the number of credits consumed by the conversion fmt.Println("Consumed credit count:", client.GetConsumedCreditCount()) // print the unique ID of the conversion fmt.Println("Job id:", client.GetJobId()) // print the size of the output in bytes fmt.Println("Output size:", client.GetOutputSize()) } func handleError(err error) { if err != nil { // report the error why, ok := err.(pdfcrowd.Error) if ok { os.Stderr.WriteString(fmt.Sprintf("Pdfcrowd Error: %s\n", why)) } else { os.Stderr.WriteString(fmt.Sprintf("Generic Error: %s\n", err)) } // rethrow or handle the exception panic(err.Error()) } }
The API can be easily integrated into your environment. You can have our interactive API Playground autogenerate the integration code for you:
The API lets you convert a web page, a local HTML file, or a string containing HTML. The result of the conversion can be stored to a local file, to a stream object or to a variable. See the conversion input section for more details.
The best way to start with the API is to choose one of the examples and once you get it working, you can further customize the code. You can find the most common customizations in the table below.
Image size | Set image dimensions with setScreenshotWidth and setScreenshotHeight. |
Image format | Specify a different output image format with setOutputFormat. |
Hide or remove elements |
You can use the following classes in your HTML
code to hide or remove elements from the output:
|
Use @media print | You can switch to the print version of the page (if it exists) with setUsePrintMedia. |
Run custom JavaScript | You can use setOnLoadJavascript or setCustomJavascript to alter the HTML contents with a custom JavaScript. In addition to the standard browser APIs, the custom JavaScript code can use helper functions from our JavaScript library . |
Custom CSS styling |
You can alter CSS styling used during conversion
with a custom JavaScript or using the
pdfcrowd-body
CSS class, which is automatically set on the HTML
<body> element. You can, for example, set
the H1 height to 48px by adding the following line
to your CSS:
.pdfcrowd-body h1 { font-size: 48px; }
|
The API enables rendering of HTML templates. The template syntax is based on the Jinja template rendering engine.
The most common constructs are:
Invoice: {{ invoice.number }}
{% for invoice in invoices %} ... {% endfor %}
{% if invoice.total > 100 %} ... {% endif %}
{{ invoice.to.first_name|capitalize }}
The supported input data formats are JSON, XML, CSV and YAML. The data can be uploaded from a file or from a string variable.
Supported template filters: capitalize, center, default, escape, first, forceescape, format, indent, join, last, length, list, lower, replace, reverse, safe, slice, sort, string, striptags, title, trim, truncate, unique, upper, wordcount, wordwrap.
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // create the API client instance client := pdfcrowd.NewHtmlToPdfClient("{{ user_name }}", "{{ api_key }}") // configure the conversion client.SetDataString(`{ "name": "World", "product": "Pdfcrowd API" }`) // run the conversion and write the result to a file err := client.ConvertStringToFile("Hello {{ name }} from {{ product }}", "output.pdf") // check for the conversion error handleError(err) } func handleError(err error) { if err != nil { // report the error why, ok := err.(pdfcrowd.Error) if ok { os.Stderr.WriteString(fmt.Sprintf("Pdfcrowd Error: %s\n", why)) } else { os.Stderr.WriteString(fmt.Sprintf("Generic Error: %s\n", err)) } // rethrow or handle the exception panic(err.Error()) } }
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // create the API client instance client := pdfcrowd.NewHtmlToPdfClient("{{ user_name }}", "{{ api_key }}") // configure the conversion client.SetDataString(`<?xml version="1.0" encoding="UTF-8"?> <data> <name>World</name> <product>Pdfcrowd API</product> </data>`) // run the conversion and write the result to a file err := client.ConvertStringToFile("Hello {{ data.name }} from {{ data.product }}", "output.pdf") // check for the conversion error handleError(err) } func handleError(err error) { if err != nil { // report the error why, ok := err.(pdfcrowd.Error) if ok { os.Stderr.WriteString(fmt.Sprintf("Pdfcrowd Error: %s\n", why)) } else { os.Stderr.WriteString(fmt.Sprintf("Generic Error: %s\n", err)) } // rethrow or handle the exception panic(err.Error()) } }
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // create the API client instance client := pdfcrowd.NewHtmlToPdfClient("{{ user_name }}", "{{ api_key }}") // configure the conversion client.SetDataString(`name: World product: Pdfcrowd API`) // run the conversion and write the result to a file err := client.ConvertStringToFile("Hello {{ name }} from {{ product }}", "output.pdf") // check for the conversion error handleError(err) } func handleError(err error) { if err != nil { // report the error why, ok := err.(pdfcrowd.Error) if ok { os.Stderr.WriteString(fmt.Sprintf("Pdfcrowd Error: %s\n", why)) } else { os.Stderr.WriteString(fmt.Sprintf("Generic Error: %s\n", err)) } // rethrow or handle the exception panic(err.Error()) } }
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // create the API client instance client := pdfcrowd.NewHtmlToPdfClient("{{ user_name }}", "{{ api_key }}") // configure the conversion client.SetDataString(`name,product World,Pdfcrowd API`) // run the conversion and write the result to a file err := client.ConvertStringToFile("Hello {{ name }} from {{ product }}", "output.pdf") // check for the conversion error handleError(err) } func handleError(err error) { if err != nil { // report the error why, ok := err.(pdfcrowd.Error) if ok { os.Stderr.WriteString(fmt.Sprintf("Pdfcrowd Error: %s\n", why)) } else { os.Stderr.WriteString(fmt.Sprintf("Generic Error: %s\n", err)) } // rethrow or handle the exception panic(err.Error()) } }
// call the API // print error os.Stderr.WriteString(fmt.Sprintf("Pdfcrowd Error: %s\n", why)) // print just error code os.Stderr.WriteString(fmt.Sprintf("Pdfcrowd Error Code: %v\n", why.getCode())) // print just error message os.Stderr.WriteString(fmt.Sprintf("Pdfcrowd Error Message: %v\n", why.getMessage())) // or handle the error in your way
libPdfcrowd.highlightHtmlElements
method call to visualize all HTML elements. See the
backgrounds example
,
borders example
and helper
JavaScript library
documentation.
Refer for details to the API Method Reference.