<?xml version="1.0" encoding="UTF-8"?><rss version="2.0"><channel><title>21pdf Engineering blog</title><description>In-depth writing on HTML-to-PDF APIs, Chromium rendering, async job models, CSS for print, invoice workflows, and production PDF infrastructure.</description><link>https://21pdf.com/</link><language>en-us</language><item><title>The best HTML to PDF API in 2026 — honestly compared</title><link>https://21pdf.com/blog/best-html-to-pdf-api-2026/</link><guid isPermaLink="true">https://21pdf.com/blog/best-html-to-pdf-api-2026/</guid><description>An opinionated comparison of six HTML-to-PDF APIs worth evaluating in 2026 — DocRaptor, PDFShift, PDFCrowd, API2PDF, Prince, 21pdf — scored on what matters.</description><pubDate>Fri, 24 Apr 2026 00:00:00 GMT</pubDate><category>best html to pdf api</category><category>html to pdf api comparison</category><category>docraptor alternative</category><category>pdfshift alternative</category><category>pdfcrowd alternative</category><category>api2pdf alternative</category><category>prince pdf alternative</category><category>html to pdf api 2026</category></item><item><title>How Chromium renders HTML into a PDF — architecture deep-dive</title><link>https://21pdf.com/blog/chromium-headless-pdf-architecture/</link><guid isPermaLink="true">https://21pdf.com/blog/chromium-headless-pdf-architecture/</guid><description>A working engineer&apos;s walk through the pipeline that turns HTML into a PDF inside headless Chromium — Blink, V8, print preview, CDP, Puppeteer.</description><pubDate>Fri, 24 Apr 2026 00:00:00 GMT</pubDate><category>chromium pdf api</category><category>chrome headless pdf</category><category>puppeteer html to pdf</category><category>playwright pdf generation</category><category>chrome devtools protocol pdf</category><category>headless browser pdf</category><category>how chromium renders pdf</category><category>puppeteer vs playwright pdf</category></item><item><title>CSS for print — @page, margins, page-breaks, the complete guide</title><link>https://21pdf.com/blog/css-print-complete-guide/</link><guid isPermaLink="true">https://21pdf.com/blog/css-print-complete-guide/</guid><description>Everything working engineers need to know about CSS for PDF output — @page rules, margins, page-breaks, headers, footers, page numbers, paged media.</description><pubDate>Fri, 24 Apr 2026 00:00:00 GMT</pubDate><category>css @page rule pdf</category><category>css for print pdf</category><category>css page break html to pdf</category><category>html to pdf margins</category><category>html to pdf header footer</category><category>html to pdf page numbers</category><category>css paged media</category><category>break-inside avoid pdf</category></item><item><title>DocRaptor alternatives — 5 options and when each wins in 2026</title><link>https://21pdf.com/blog/docraptor-alternative/</link><guid isPermaLink="true">https://21pdf.com/blog/docraptor-alternative/</guid><description>Fair comparison of DocRaptor alternatives — 21pdf, PDFShift, PDFCrowd, API2PDF, self-hosted Prince — with pricing, features, and the decision framework.</description><pubDate>Fri, 24 Apr 2026 00:00:00 GMT</pubDate><category>docraptor alternative</category><category>docraptor competitors</category><category>html to pdf api</category><category>prince xml alternative</category><category>docraptor pricing</category><category>cheaper than docraptor</category></item><item><title>HTML to PDF API — the complete 2026 guide</title><link>https://21pdf.com/blog/html-to-pdf-api-guide/</link><guid isPermaLink="true">https://21pdf.com/blog/html-to-pdf-api-guide/</guid><description>Everything a working engineer needs to know about HTML-to-PDF APIs in 2026 — how they render, what to ask, and the pitfalls that actually bite in production.</description><pubDate>Fri, 24 Apr 2026 00:00:00 GMT</pubDate><category>html to pdf api</category><category>convert html to pdf api</category><category>rest api html to pdf</category><category>best html to pdf api</category><category>html to pdf api free</category><category>pdf api pricing</category><category>chromium pdf api</category></item><item><title>HTML to PDF in Go — 3 options and the one most teams should pick</title><link>https://21pdf.com/blog/html-to-pdf-golang/</link><guid isPermaLink="true">https://21pdf.com/blog/html-to-pdf-golang/</guid><description>Convert HTML to PDF in Go with chromedp, rod, or a managed HTML-to-PDF API — full working code, comparison, and when to pick each.</description><pubDate>Fri, 24 Apr 2026 00:00:00 GMT</pubDate><category>html to pdf golang</category><category>go html to pdf</category><category>chromedp pdf</category><category>rod pdf golang</category><category>convert html to pdf go</category><category>golang pdf generation</category></item><item><title>HTML to PDF library vs API — when self-host wins, when it doesn&apos;t</title><link>https://21pdf.com/blog/html-to-pdf-library-vs-api/</link><guid isPermaLink="true">https://21pdf.com/blog/html-to-pdf-library-vs-api/</guid><description>A structured comparison of self-hosting Puppeteer/Playwright/Gotenberg vs using a managed HTML-to-PDF API — with the numbers that matter for the decision.</description><pubDate>Fri, 24 Apr 2026 00:00:00 GMT</pubDate><category>html to pdf vs pdf library</category><category>self-host puppeteer pdf</category><category>gotenberg vs pdf api</category><category>pdf generation microservice</category><category>pdf library or api</category><category>when to self-host pdf rendering</category><category>puppeteer in production</category></item><item><title>HTML to PDF in Node.js — the practical 2026 guide</title><link>https://21pdf.com/blog/html-to-pdf-nodejs/</link><guid isPermaLink="true">https://21pdf.com/blog/html-to-pdf-nodejs/</guid><description>Four ways to turn HTML into a PDF from Node.js — Puppeteer, Playwright, html-pdf-node, and a managed API — with working code and when to pick each.</description><pubDate>Fri, 24 Apr 2026 00:00:00 GMT</pubDate><category>html to pdf nodejs</category><category>node html to pdf</category><category>puppeteer pdf nodejs</category><category>playwright pdf nodejs</category><category>html-pdf-node</category><category>convert html to pdf javascript</category><category>nodejs pdf generation</category></item><item><title>HTML to PDF in Python — 4 options compared, with working code</title><link>https://21pdf.com/blog/html-to-pdf-python/</link><guid isPermaLink="true">https://21pdf.com/blog/html-to-pdf-python/</guid><description>Convert HTML to PDF in Python with Playwright, WeasyPrint, pdfkit (wkhtmltopdf), or a managed API — full working code and when to pick each.</description><pubDate>Fri, 24 Apr 2026 00:00:00 GMT</pubDate><category>html to pdf python</category><category>python html to pdf</category><category>weasyprint</category><category>playwright python pdf</category><category>pdfkit python</category><category>wkhtmltopdf python</category><category>convert html to pdf python</category></item><item><title>Generating invoice PDFs from an API — the complete playbook</title><link>https://21pdf.com/blog/invoice-pdf-api-guide/</link><guid isPermaLink="true">https://21pdf.com/blog/invoice-pdf-api-guide/</guid><description>A production playbook for generating invoice PDFs via an HTML-to-PDF API — template structure, US sales tax, EU VAT invoicing, edge cases, and delivery.</description><pubDate>Fri, 24 Apr 2026 00:00:00 GMT</pubDate><category>invoice pdf generator api</category><category>generate invoice pdf from html</category><category>invoice pdf api</category><category>vat invoice pdf api</category><category>eu invoice requirements</category><category>us sales tax invoice</category><category>automated invoice pdf</category><category>html invoice template</category></item><item><title>PDF rendering at scale — architecture for 1M PDFs/day</title><link>https://21pdf.com/blog/pdf-at-scale/</link><guid isPermaLink="true">https://21pdf.com/blog/pdf-at-scale/</guid><description>Operating an HTML-to-PDF service at production scale — queue design, Chromium pool sizing, rate limits, SSRF, monitoring, and the failure modes that actually bite.</description><pubDate>Fri, 24 Apr 2026 00:00:00 GMT</pubDate><category>pdf rendering at scale</category><category>pdf generation microservice</category><category>async pdf job queue</category><category>chromium pool management</category><category>pdf rate limit api</category><category>pdf webhook vs polling</category><category>production pdf infrastructure</category><category>pdf worker pool</category></item><item><title>PDFShift alternatives — 5 options compared honestly in 2026</title><link>https://21pdf.com/blog/pdfshift-alternative/</link><guid isPermaLink="true">https://21pdf.com/blog/pdfshift-alternative/</guid><description>Fair comparison of PDFShift alternatives — 21pdf, PDFCrowd, DocRaptor, API2PDF, self-hosted — with pricing, feature gaps, and migration guidance.</description><pubDate>Fri, 24 Apr 2026 00:00:00 GMT</pubDate><category>pdfshift alternative</category><category>pdfshift competitors</category><category>html to pdf api</category><category>pdfshift pricing</category><category>cheaper than pdfshift</category></item><item><title>SSRF in HTML-to-PDF renderers — two layers, not one</title><link>https://21pdf.com/blog/ssrf-pdf-renderers/</link><guid isPermaLink="true">https://21pdf.com/blog/ssrf-pdf-renderers/</guid><description>Why HTML-to-PDF services are especially SSRF-prone, the two layers every vendor should implement, and the attack classes that bite the single-layer ones.</description><pubDate>Fri, 24 Apr 2026 00:00:00 GMT</pubDate><category>ssrf in pdf generator</category><category>ssrf pdf renderer</category><category>pdf api security</category><category>puppeteer ssrf</category><category>server side request forgery pdf</category><category>pdf api dns rebinding</category></item></channel></rss>