Use Nutrient DWS Processor API to render HTML pages and CSS templates as WebP image output for web-optimized screenshots and previews. Start free with 50 monthly credits — no credit card, watermarked output — and move to production with credit-based pricing.
Render HTML and CSS into WebP images for lightweight, web-optimized screenshots and thumbnail workflows.
Use REST, Postman, curl, JavaScript, Python, Java, C#, PHP, or HTTP to automate conversion inside larger document processing pipelines.
This conversion is one action in the DWS Processor API. Combine it with other conversions, OCR, extraction, and editing in a single request.
This example will convert your HTML file to a WebP image.
Try it out in three steps
index.html to your project folder.result.webp to see the output.curl -X POST https://api.nutrient.io/build \ -H "Authorization: Bearer your_api_key_here" \ -o image.webp \ --fail \ -F document=@index.html \ -F instructions='{ "parts": [ { "html": "document" } ], "output": { "type": "image", "format": "webp", "dpi": 500 } }'curl -X POST https://api.nutrient.io/build ^ -H "Authorization: Bearer your_api_key_here" ^ -o image.webp ^ --fail ^ -F document=@index.html ^ -F instructions="{\"parts\": [{\"html\": \"document\"}], \"output\": {\"type\": \"image\", \"format\": \"webp\", \"dpi\": 500}}"package com.example.pspdfkit;
import java.io.File;import java.io.IOException;import java.nio.file.FileSystems;import java.nio.file.Files;import java.nio.file.StandardCopyOption;
import org.json.JSONArray;import org.json.JSONObject;
import okhttp3.MediaType;import okhttp3.MultipartBody;import okhttp3.OkHttpClient;import okhttp3.Request;import okhttp3.RequestBody;import okhttp3.Response;
public final class PspdfkitApiExample { public static void main(final String[] args) throws IOException { final RequestBody body = new MultipartBody.Builder() .setType(MultipartBody.FORM) .addFormDataPart( "document", "index.html", RequestBody.create( MediaType.parse("text/html"), new File("index.html") ) ) .addFormDataPart( "instructions", new JSONObject() .put("parts", new JSONArray() .put(new JSONObject() .put("html", "document") ) ) .put("output", new JSONObject() .put("type", "image") .put("format", "webp") .put("dpi", 500) ).toString() ) .build();
final Request request = new Request.Builder() .url("https://api.nutrient.io/build") .method("POST", body) .addHeader("Authorization", "Bearer your_api_key_here") .build();
final OkHttpClient client = new OkHttpClient() .newBuilder() .build();
final Response response = client.newCall(request).execute();
if (response.isSuccessful()) { Files.copy( response.body().byteStream(), FileSystems.getDefault().getPath("image.webp"), StandardCopyOption.REPLACE_EXISTING ); } else { // Handle the error throw new IOException(response.body().string()); } }}using System;using System.IO;using System.Net;using RestSharp;
namespace PspdfkitApiDemo{ class Program { static void Main(string[] args) { var client = new RestClient("https://api.nutrient.io/build");
var request = new RestRequest(Method.POST) .AddHeader("Authorization", "Bearer your_api_key_here") .AddFile("document", "index.html") .AddParameter("instructions", new JsonObject { ["parts"] = new JsonArray { new JsonObject { ["html"] = "document" } }, ["output"] = new JsonObject { ["type"] = "image", ["format"] = "webp", ["dpi"] = 500 } }.ToString());
request.AdvancedResponseWriter = (responseStream, response) => { if (response.StatusCode == HttpStatusCode.OK) { using (responseStream) { using var outputFileWriter = File.OpenWrite("image.webp"); responseStream.CopyTo(outputFileWriter); } } else { var responseStreamReader = new StreamReader(responseStream); Console.Write(responseStreamReader.ReadToEnd()); } };
client.Execute(request); } }}// This code requires Node.js. Do not run this code directly in a web browser.
const axios = require('axios')const FormData = require('form-data')const fs = require('fs')
const formData = new FormData()formData.append('instructions', JSON.stringify({ parts: [ { html: "document" } ], output: { type: "image", format: "webp", dpi: 500 }}))formData.append('document', fs.createReadStream('index.html'))
;(async () => { try { const response = await axios.post('https://api.nutrient.io/build', formData, { headers: formData.getHeaders({ 'Authorization': 'Bearer your_api_key_here' }), responseType: "stream" })
response.data.pipe(fs.createWriteStream("image.webp")) } catch (e) { const errorString = await streamToString(e.response.data) console.log(errorString) }})()
function streamToString(stream) { const chunks = [] return new Promise((resolve, reject) => { stream.on("data", (chunk) => chunks.push(Buffer.from(chunk))) stream.on("error", (err) => reject(err)) stream.on("end", () => resolve(Buffer.concat(chunks).toString("utf8"))) })}import requestsimport json
response = requests.request( 'POST', 'https://api.nutrient.io/build', headers = { 'Authorization': 'Bearer your_api_key_here' }, files = { 'document': open('index.html', 'rb') }, data = { 'instructions': json.dumps({ 'parts': [ { 'html': 'document' } ], 'output': { 'type': 'image', 'format': 'webp', 'dpi': 500 } }) }, stream = True)
if response.ok: with open('image.webp', 'wb') as fd: for chunk in response.iter_content(chunk_size=8096): fd.write(chunk)else: print(response.text) exit()<?php
$FileHandle = fopen('image.webp', 'w+');
$curl = curl_init();
curl_setopt_array($curl, array( CURLOPT_URL => 'https://api.nutrient.io/build', CURLOPT_CUSTOMREQUEST => 'POST', CURLOPT_RETURNTRANSFER => true, CURLOPT_ENCODING => '', CURLOPT_POSTFIELDS => array( 'instructions' => '{ "parts": [ { "html": "document" } ], "output": { "type": "image", "format": "webp", "dpi": 500 } }', 'document' => new CURLFILE('index.html') ), CURLOPT_HTTPHEADER => array( 'Authorization: Bearer your_api_key_here' ), CURLOPT_FILE => $FileHandle,));
$response = curl_exec($curl);
curl_close($curl);
fclose($FileHandle);POST https://api.nutrient.io/build HTTP/1.1Content-Type: multipart/form-data; boundary=--customboundaryAuthorization: Bearer your_api_key_here
--customboundaryContent-Disposition: form-data; name="instructions"Content-Type: application/json
{ "parts": [ { "html": "document" } ], "output": { "type": "image", "format": "webp", "dpi": 500 }}--customboundaryContent-Disposition: form-data; name="document"; filename="index.html"Content-Type: text/html
(document data)--customboundary--Most common next steps
Use the following:
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Nutrient’s infrastructure is SOC 2 Type 2 audited and GDPR-compliant. See our privacy policy and security documentation for details on data handling.
All communication between your application and Nutrient is done via HTTPS to ensure your data is encrypted when it’s sent to us.
All payments are handled by Paddle. Nutrient DWS Processor API never has direct access to any of your payment data.
Send your HTML markup or a page URL to the HTML-to-WebP API, and it renders the content as a WebP image. See the getting started guide to make your first request.
Yes. Use the HTML-to-image API to render HTML as JPG, PNG, or TIFF in addition to WebP.
Yes. Use the HTML-to-PDF API when you need a document rather than an image.
Call the API over REST or HTTP and integrate it with Java, C#, JavaScript, Python, and PHP, or start in Postman. See supported languages.
It uses the credit-based DWS Processor pricing, with a free tier for evaluation. See Processor API pricing.
Create an account to get your DWS Processor API key and start making API calls.