Developer tools · New
Bhowra.Ink is a complete HTML-to-PDF rendering engine in a single managed .NET assembly, under 1 MB with global fonts baked in. No Chromium, no Node.js, no native binaries, no third-party packages — one DLL that turns your HTML and CSS into production-quality PDFs anywhere .NET 8 runs.
Get started
Install from NuGet, call one method. No configuration required.
// dotnet add package Bhowra.Ink
using Bhowra.Ink;
string html = "<h1>Invoice #1024</h1><p>Total due: <b>£1,240.00</b></p>";
byte[] pdf = HtmlConverter.ConvertToBytes(html);
File.WriteAllBytes("invoice.pdf", pdf);using Bhowra.Ink;
var result = HtmlConverter.Convert(html, new ConverterProperties
{
BaseUri = "C:/site/assets", // resolve <img>/<link> relative paths
Title = "Invoice 1024",
});
if (result.Success)
result.SaveToFile("invoice.pdf"); // result.PageCount, result.SizeBytes also availableTry it live
A free online HTML to PDF converter, right in your browser — edit the HTML on the left and hit Render PDF. Converted by the pure-C# engine; no install, no sign-up.
Rendered server-side by the under 1 MB pure-C# library on Azure Functions. Remote images are
blocked for safety — inline them as data: URIs.
Most .NET HTML-to-PDF solutions are a headless Chrome wrapper in disguise. That means shipping a full browser with every deployment: hundreds of megabytes of binaries, multi-second cold starts, half a gigabyte of RAM per render, and a browser security patch cycle that is now your patch cycle. And on serverless platforms it often simply doesn't work — headless Chromium is famously blocked on the Azure Functions and Azure App Service sandbox on Windows Consumption plans.
The traditional alternative — heavyweight PDF suites — brings its own friction: multi-package dependency trees, large assemblies, and restrictive or per-everything licensing.
Bhowra.Ink takes a third path: a from-scratch HTML5 parser, CSS engine, layout engine and PDF writer, written entirely in C# against the .NET 8 base class library. The library is the renderer.
Why Bhowra.Ink
Runs where browser-based converters can't — Windows Consumption plans, sandboxed App Service, AWS Lambda, and locked-down containers. 100% managed code with no P/Invoke, GDI, or native binaries. Activate via the BHOWRA_LICENSE_KEY app setting on Azure — no sidecar process, nothing to install.
One under 1 MB managed assembly, global fonts included — zero NuGet dependencies in the .csproj. No transitive packages to audit, no version conflicts to resolve, and no AGPL licensing that forces your application code open. One package, one license, no surprises.
Identical HTML always produces the identical PDF binary — across runs, machines, and .NET versions. Cache by input hash, verify documents by comparing checksums, and write golden-file tests that actually catch regressions. No browser version drift, no sub-pixel rendering surprises.
Full bidirectional text layout for Arabic and Hebrew is bundled — no extra packages, no manual font wiring. Verified on ZATCA tax invoices and UAE/Saudi payslips. Latin, Devanagari, and Thai fonts are embedded, covering South Asia and Southeast Asia markets with zero setup.
Generate archival PDF/A-2B for regulatory retention, tagged PDF/UA for accessibility mandates, and AES-256 encrypted PDFs with owner and user passwords — all from a single assembly. XMP metadata and modern cross-reference streams keep every document standards-compliant across PDF 1.4 through 2.0. Externally validated by veraPDF — 2,147 checks passed.
| Bhowra.Ink | Chromium-based converters | Traditional PDF suites | |
|---|---|---|---|
| Deployment size | under 1 MB, one DLL | Hundreds of MB (full browser) | Tens of MB, multiple packages |
| Third-party dependencies | None (no AGPL) | Browser + driver + Node or native libs | Multi-package dependency trees, often AGPL-licensed |
| Azure Functions (Windows Consumption) | ✅ Works | ❌ Blocked by sandbox | ⚠️ Varies |
| Cold start | ~1 s (first call, incl. JIT) | Seconds (browser spawn) | Varies |
| Memory per conversion | Tens of MB | ~0.5–1 GB per browser instance | Varies |
| Deterministic output | ✅ Byte-identical | ❌ Varies by browser version | ⚠️ Varies |
| Security patching | One small managed DLL | An entire browser's CVE stream | Vendor cadence |
| JavaScript execution | ❌ By design (see FAQ) | ✅ | ⚠️ Varies |
E-invoicing
Generate the human-readable invoice PDF that modern e-invoicing mandates require — with the structured XML embedded and a scannable QR code, all in pure C#.
Archival PDF with your CII / UBL XML embedded (/AFRelationship), the form ZATCA requires when sharing an invoice with the buyer.
Embed factur-x.xml at the right conformance profile. The PDF is the legal invoice — compliant with EN 16931 and XRechnung.
ISO/IEC 18004 QR generator (byte mode, versions 1–40, EC L/M/Q/H) built in — no extra library needed for the ZATCA TLV QR or any other QR-coded document.
Production-grade shaping and bidi layout for bilingual GCC invoices. Verified on ZATCA tax invoices and UAE/Saudi payslips — no extra packages required.
Bhowra.Ink renders the invoice PDF and embeds your XML. Signing and tax-authority submission remain your pipeline’s responsibility.
Spec-correct parser with the real error-recovery algorithms (adoption agency,
foster parenting), the HTML5 named-entity table,
<template> handling, optional-end-tag
rules, tables with rowspan/colspan,
lists, semantic elements.
TrueType, OpenType, WOFF and WOFF2 font embedding; automatic subsetting for small files; full-Unicode Type0/CIDFontType2 embedding with ToUnicode maps so text in the PDF copies, searches and extracts correctly.
CSS Grid with a unified track engine — fr/minmax()/auto
tracks, align-content, spans that grow the implicit grid, and
content-sized columns when no grid-template-columns is given.
Flexbox with row/column direction, wrapping, and every justify-content
mode including space-between/around/evenly.
A design wider than the page shrinks to fit automatically
(ConverterProperties.PageScaling), with links and bookmarks
scaled to match.
<link rel="stylesheet"> and
@import are fetched and folded into the cascade in document
order. Local files by default; remote fetches are opt-in and SSRF-guarded — private/link-local/
cloud-metadata addresses blocked, redirects re-validated, per-file and total byte caps, import-cycle
and depth guards.
JPEG (grayscale/RGB/CMYK with Exif), PNG (every bit depth, interlacing, full alpha),
WebP (lossless / VP8L), GIF, BMP, inline SVG shapes and strokes, EXIF auto-orientation, parallel
async downloads, and a pluggable ImageFetcher
delegate for private blob storage. TIFF and JPEG-2000 not decoded. Also available standalone:
ImageToPdf turns one or more images directly into a PDF —
Contain/Cover/Stretch/None fit modes, one image per page, no HTML required.
Linear, radial and conic gradients rendered as true PDF shadings (not
rasterized), CSS transforms and filter: blur(), box-shadow with real Gaussian blur, per-corner
border radius, per-side dashed/dotted/double borders, outlines, opacity,
text-overflow: ellipsis,
word-break/overflow-wrap, ::before/::after with
content counters, SVG clipPath / <use> / <symbol>.
@page size/margins/margin-boxes, page counters,
named page sizes (A4/Letter/Legal/landscape), headers/footers in HTML styled by
your document's own CSS, widows/orphans,
break-inside: avoid, repeating table headers. Note:
border-collapse: collapse shared-border dedup is not yet optimized.
sRGB, device-cmyk() for print workflows,
embedded sRGB ICC output intent for PDF/A.
Versions 1.4–2.0, classic and cross-reference-stream xref, Flate compression (50–75% smaller files), document metadata + XMP, encryption (AES-256 and legacy RC4), watermarks, bookmarks/outline, link annotations, embedded file attachments, tagged structure trees for accessibility, PDF/A-2B and PDF/UA-1 modes. Fillable AcroForm fields (radio, checkbox, text, dropdown) generated from HTML inputs.
Per-developer annual subscription. Unlimited deployments on every tier. Full-featured free trial — no sales call required.
Site and OEM answer different questions. Site is about how many people write the code. OEM is about who runs it. If the DLL executes on a machine your organization doesn’t operate, you need OEM — whatever your team size.
Solo developers & freelancers
For a single developer. Client work is included, provided you run the conversion.
Product teams up to 5 developers
For a product team of up to five developers.
One organization, unlimited developers
Unlimited developers across one legal entity and its wholly-owned subsidiaries.
Redistribute inside your own software
For software that runs on infrastructure you do not operate — desktop, on-premise, resold SDKs.
Not ready to buy? Install the trial from NuGet → Fully functional, with a watermark.
Desktop or mobile apps you sell · on-prem or customer-hosted installs · Docker images and Helm charts your customers run themselves · air-gapped deployments · SDKs and plugins you distribute
Anything running on infrastructure your organization operates — including the SaaS you sell, and private cloud
These are honest gaps, not deal-breakers — but worth calling out upfront:
No — by design. Bhowra.Ink renders static HTML + CSS, which is what server-generated documents (invoices, reports, statements, contracts) are. No script engine also means no script attack surface: untrusted HTML can't execute anything. If you need to render a JavaScript single-page app, pre-render it to HTML first or use a browser-based tool.
Anything that runs .NET 8 or later: Windows, Linux, macOS, Azure Functions and App Service (including Windows Consumption plans), AWS Lambda, Docker/Kubernetes. There is no native code, so there are no per-platform builds.
Per-developer annual subscription with unlimited deployments. Activate with a
single key — BhowraHtmlConverter.Initialize(key)
at startup, or just set the BHOWRA_LICENSE_KEY
app setting on Azure. Without a key the library runs in trial mode: fully
functional, with a watermark. Perpetual licenses are
available on request — write to
sales@bhowra.com.
The engine ships with 1,400+ automated tests including byte-identity golden
files, and the optional ValidateContent flag
re-reads the generated PDF after every conversion and verifies every visible
word of your HTML is present and readable — catching white-on-white text,
clipped sections, or dropped content automatically.
Conversion happens entirely in your process. Nothing about your documents is
sent anywhere. The only outbound calls the library ever makes are the image
URLs in your HTML (overridable via
ImageFetcher) and license activation.
Bhowra.Ink is a single under 1 MB managed DLL with global fonts embedded, zero dependencies, a real CSS engine, and PDF/A-2B and PDF/UA output. Unlike heavyweight PDF suites, there's no multi-package dependency tree, no per-feature licensing, and no AGPL entanglement — and it runs on Azure Functions where browser-based converters can't.
Keep exploring
Add Bhowra.Ink to your project, convert your first document in under a minute, and ship it to production on the smallest serverless plan you can find.