From request to document.

Authentication

Create an account and open your workspace. Send the API key in the Authorization header. Keep it on your server, never in public browser code.

Authorization: Bearer YOUR_API_KEY
Content-Type: application/json

Base URL: https://pdf.kvadrati.com

HTML → PDF

Send HTML and an optional filename. The result is a binary A4 PDF with backgrounds included.

{
  "html": "<html><body><h1>Hello PDF</h1></body></html>",
  "fileName": "report.pdf"
}

200 OK · Content-Type: application/pdf

URL → PDF

Send a publicly accessible URL. The service fetches its HTML and resolves relative resource links. Pages requiring sign-in or an interactive session are not suitable.

{
  "url": "https://example.com/report",
  "fileName": "report.pdf"
}

The URL must use HTTP or HTTPS. Only use content you are authorised to access and convert.

Integration examples

cURL

curl https://pdf.kvadrati.com/pdf/from-html \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"html":"<h1>Hello PDF</h1>","fileName":"report.pdf"}' \
  --output report.pdf

Python

import os
import requests

response = requests.post(
    "https://pdf.kvadrati.com/pdf/from-html",
    headers={"Authorization": "Bearer " + os.environ["PDF_API_KEY"]},
    json={"html": "<h1>Hello PDF</h1>", "fileName": "report.pdf"},
    timeout=60,
)
response.raise_for_status()
with open("report.pdf", "wb") as file:
    file.write(response.content)

C# / .NET 10

using System.Net.Http.Headers;
using System.Net.Http.Json;

using var client = new HttpClient();
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue(
    "Bearer", Environment.GetEnvironmentVariable("PDF_API_KEY"));
using var response = await client.PostAsJsonAsync(
    "https://pdf.kvadrati.com/pdf/from-html",
    new { html = "<h1>Hello PDF</h1>", fileName = "report.pdf" });
response.EnsureSuccessStatusCode();
await File.WriteAllBytesAsync("report.pdf", await response.Content.ReadAsByteArrayAsync());

Limits and errors

A free account has 2 conversions per day. The daily period uses UTC; a failed conversion can consume an attempt. Enquire for higher volumes.

Check HTTP status before saving a response. Error responses are not PDF files.

A simple service availability check, without an API key.