PD4ML Compared with Other HTML-to-PDF Libraries
Choosing a Java HTML to PDF library comes down to four questions: how faithfully it lays out your HTML and CSS, which PDF standards it can produce (PDF/A, PDF/UA, ZUGFeRD), which other formats you need besides PDF, and what the license costs over time. This page compares PD4ML with the libraries teams most often evaluate alongside it: iText with pdfHTML, PDFreactor, Aspose.HTML for Java, BFO Publisher and Report Generator, and the open-source OpenHTMLtoPDF.
The comparison covers PD4ML v4.1.1 and, marked 4.2, features of the upcoming PD4ML 4.2 with its new v42 layout engine. Competitor information comes from their public documentation and price lists as of November 2026; a cell marked "not verified" means we could not confirm it from public sources, not that the feature is missing.
At a glance
- PD4ML is a pure-Java layout engine with no browser, no native code and no rendering service. One parse writes PDF, DOCX, RTF and images. Licenses are perpetual, one-time fees from €100.
- iText with pdfHTML converts HTML into iText's layout objects. It is a large PDF toolkit, dual-licensed under AGPL or a commercial subscription quoted per customer.
- PDFreactor is a commercial HTML-to-PDF server and library with a JavaScript engine and deep CSS Paged Media support, sold as an annual subscription.
- Aspose.HTML for Java is an HTML processing toolkit with a W3C DOM, scripting and conversion to PDF, XPS, DOCX and images.
- BFO Publisher is a pure-Java CSS layout engine for HTML and XML; BFO Report Generator is BFO's older XML-based report engine.
- OpenHTMLtoPDF is a free, LGPL fork of Flying Saucer that renders XHTML and CSS 2.1 to PDF through Apache PDFBox.
PD4ML vs. iText, PDFreactor, Aspose, BFO and OpenHTMLtoPDF: licensing and price
List prices without VAT. iText and BFO's external and OEM licenses are quoted per customer; the figures below are reference points.
| Item | PD4ML | iText + pdfHTML | PDFreactor | Aspose.HTML Java | BFO Publisher / RG | OpenHTMLtoPDF |
|---|---|---|---|---|---|---|
| License model | Perpetual, one-time fee | AGPL or commercial subscription (quote) | Annual subscription | Perpetual, 1 year of maintenance | Perpetual per server (internal), subscription (external) | LGPL 2.1, free |
| Entry price | €100 (STD), €220 (UA, accessible PDF) | Not published; reported median ≈ $17,600 per year | Pro $1,908 per year | $979 (1 developer, 1 location) | Report Generator $1,617, Publisher $3,430 per server | Free |
| Unlimited deployments | Site €1,600–3,200, Enterprise €8,000–16,000 | Volume-based quote; reported ≈ $7,300–32,700 per year | Premium $4,788, Cluster $15,588 per year | Site Small Business $4,895; OEM tiers higher | Unlimited license on request (annual) | Free |
| Source code license | Supported Site €6,000–8,000, Enterprise €30,000–35,000 | Supported Open source (AGPL) | Not supported | Not supported Escrow only | Not supported | Supported |
| Free evaluation | All features, watermarked output | 30-day trial or AGPL | Evaluation license; free personal license | Temporary license | Fully functional demo | Not needed |
See PD4ML editions and prices for what each edition (STD, PRO, DMS, UA) includes.
Rendering engine and architecture
| Feature | PD4ML | iText + pdfHTML | PDFreactor | Aspose.HTML Java | BFO Publisher / RG | OpenHTMLtoPDF |
|---|---|---|---|---|---|---|
| Rendering engine | Own print-focused engines: v40 (default) and v42 (Chrome-verified layout) | Own CSS parser feeding iText layout objects | Own engine | Own engine, "headless browser" model | Own CSS layout engine | Flying Saucer fork |
| HTML parser | Supported Tolerant HTML5 parser; honours <meta charset> 4.2 |
Supported jsoup-based | Supported HTML5 and XML | Supported HTML5 and XHTML | Supported HTML5 (repairing) or strict XML; RG: XML only | Partial or add-on Well-formed XHTML; HTML5 through a jsoup adapter |
| XML with XSLT input | Supported | Not supported | Supported | Partial or add-on XHTML only | Supported XSLT and XInclude | Not supported |
| JavaScript execution | Not supported No script engine; PDF document actions only | Not supported | Supported Canvas, chart libraries, MathJax | Supported | Not verified | Not supported |
| DOM API before conversion | Supported get: selectors, inner, attributes 4.2 |
Partial or add-on Tag workers, CSS appliers, convert |
Partial or add-on Through JavaScript | Supported W3C DOM, XPath, CSS selectors | Not supported | Partial or add-on Accepts a W3C DOM |
| Layout read-back | Supported layout(): element boxes per page, computed style 4.2 |
Not supported | Not verified | Not verified | Not supported | Not supported |
| Parse once, write many formats | Supported PDF, DOCX, RTF and images from one parse | Not supported | Not verified | Partial or add-on Load once, convert per format | Not verified | Not supported |
| Minimum Java | Java 8 (TIFF output Java 9) | Java 8 | Current JRE | Separate builds per JDK | Current JRE | Java 8 |
| Dependencies | Single jar plus Bouncy Castle | iText Core modules | Bundled | Large single jar | Few third-party libraries | PDFBox plus plugin libraries |
PD4ML's two-phase model reads and lays out a document once and writes it to several formats. With PD4ML 4.2 the parsed document can be read and changed before conversion.
HTML and CSS layout support
| Feature | PD4ML | iText + pdfHTML | PDFreactor | Aspose.HTML Java | BFO Publisher / RG | OpenHTMLtoPDF |
|---|---|---|---|---|---|---|
| Flexbox | Supported | Supported Including vertical pagination | Supported | Not verified | Supported | Not supported |
| CSS Grid | Supported Template areas, line names, dense placement 4.2: 3,609 of 3,758 WebKit grid tests pass | Partial or add-on No subgrid or inline-grid |
Supported | Not verified | Not verified | Not supported |
| CSS @page | Supported Size, :first/:left/:right/:blank, named pages, 16 margin boxes 4.2 |
Supported | Supported Full GCPM | Partial or add-on | Supported | Partial or add-on Page boxes, running elements |
| Running headers and page numbers | Supported HTML headers and footers with $[page] of $[total]; counter(page) in margin boxes 4.2 |
Supported Running elements, target-counter |
Supported | Partial or add-on | Supported | Partial or add-on |
| Different page sizes in one document | Supported Page scopes like "2+" or "3-7,odd" |
Supported | Supported | Partial or add-on | Supported | Supported |
| Multi-column pages | Supported | Supported | Supported | Not verified | Not verified | Not supported |
| Widow and orphan control | Supported | Supported | Supported | Partial or add-on | Supported | Supported |
| Media queries | Supported Level 4 range syntax, nested @media 4.2 |
Supported | Supported | Supported | Not verified | Partial or add-on |
| Vertical writing modes | Supported 4.2 | Not verified | Supported | Not verified | Not verified | Not supported |
| Vector SVG | Supported Built-in renderer | Supported | Supported | Supported | Supported | Supported Batik plugin |
| MathML | Supported | Not supported | Supported | Not verified | Supported | Supported Plugin |
| Image maps | Supported <area> regions become links 4.2 |
Not verified | Not verified | Not verified | Not verified | Not supported |
| Canvas, iframe, video | Not supported Shown as a labelled box | Not supported | Supported Canvas | Partial or add-on | Partial or add-on | Not supported |
| Fit a document onto one page | Supported | Not supported | Not verified | Not verified | Not verified | Not supported |
For tag-by-tag details see the PD4ML v42 HTML5 element support matrix and PD4ML's proprietary CSS properties and tags.
Output formats: PDF, DOCX, RTF and images
| Feature | PD4ML | iText + pdfHTML | PDFreactor | Aspose.HTML Java | BFO Publisher / RG | OpenHTMLtoPDF |
|---|---|---|---|---|---|---|
| Supported | Supported | Supported | Supported | Supported | Supported | |
| DOCX (Word) | Supported Editable text boxes, native SVG and form controls 4.2 | Not supported | Not supported | Supported | Not supported | Not supported |
| RTF | Supported | Not supported | Not supported | Not supported | Not supported | Not supported |
| Raster images | Supported PNG, TIFF, multi-page TIFF | Not supported | Supported | Supported JPG, PNG, BMP, TIFF, GIF | Supported | Supported |
| Other formats | Not supported | Not supported | Not supported | Supported XPS, Markdown, MHTML | Supported Multi-page SVG | Not supported |
Among the libraries compared, PD4ML is the only one that writes both DOCX and RTF from the same layout as the PDF. See also HTML to raster image conversion.
PDF/A, PDF/UA and e-invoicing standards
| Feature | PD4ML | iText + pdfHTML | PDFreactor | Aspose.HTML Java | BFO Publisher / RG | OpenHTMLtoPDF |
|---|---|---|---|---|---|---|
| PDF version control | Supported PDF 1.4 to 2.0, ISO 32000-1 extension levels 1–11 | Supported Up to 2.0 | Supported | Not verified | Supported Including 2.0 | Partial or add-on |
| PDF/A archiving | Supported PDF/A-1a/1b, 2a/2b/2u, 3a/3b/3u, 4, 4e | Supported | Supported PDF/A-1 to PDF/A-3 | Partial or add-on Through Aspose.PDF | Supported PDF/A-1 to PDF/A-4 | Supported |
| PDF/UA-1 accessible PDF | Supported Headings, lists, tables, links, images; SVG as Figure, MathML as Formula, <th> scope 4.2 |
Supported | Supported | Partial or add-on Through Aspose.PDF | Supported | Supported |
| PDF/UA-2 on PDF 2.0 | Supported | Not verified | Not verified | Not verified | Not verified | Not supported |
| PDF/A and PDF/UA combined | Supported For example PDF/A-3a with PDF/UA-1 in one call | Supported | Supported | Not verified | Supported | Not verified |
| ZUGFeRD and Factur-X | Supported Presets, including accessible PDF/A-3a invoices | Partial or add-on PDF/A-3 with an attachment, built by hand | Not supported ZUGFeRD add-on removed from current versions | Not supported | Partial or add-on PDF/A-3 attachments | Not supported |
| PDF/X for print | Not supported | Not verified | Supported PDF/X-1a, X-3, X-4 | Not supported | Supported | Not supported |
| Brotli stream compression (PDF 2.0) | Supported Opt-in, 3–31% smaller files 4.2 | Not verified | Not verified | Not verified | Not verified | Not supported |
| Conformance check after writing | Supported PDF/A status report; strict mode rejects non-conformant source | Supported | Supported | Not verified | Supported | Partial or add-on |
How to produce each standard is described under PDF/A, PDF/UA and e-invoicing formats and ZUGFeRD and Factur-X PDF invoices.
Document features
| Feature | PD4ML | iText + pdfHTML | PDFreactor | Aspose.HTML Java | BFO Publisher / RG | OpenHTMLtoPDF |
|---|---|---|---|---|---|---|
| Bookmarks | Supported From headings or anchors | Supported | Supported | Not verified | Supported | Supported |
| Hyperlinks | Supported Internal and external, in PDF and RTF | Supported | Supported | Supported | Supported | Supported |
| Table of contents | Supported Generated | Partial or add-on Through target-counter CSS |
Supported Through CSS | Not supported | Supported Through CSS | Partial or add-on |
| Footnotes and endnotes | Supported | Not verified | Supported | Not supported | Supported | Not supported |
| Watermarks | Supported Any HTML, with opacity and rotation, on screen or print only | Supported | Supported | Not verified | Supported | Partial or add-on |
| Fillable PDF forms from HTML | Supported Inputs, selects, text areas, submit and reset buttons | Supported | Supported | Not supported | Supported | Partial or add-on |
| File attachments | Supported | Supported | Supported | Not supported | Supported | Not verified |
| Metadata | Supported Including custom XMP namespaces 4.2 | Supported | Supported | Partial or add-on | Supported | Partial or add-on |
| Inject HTML and template data | Supported inject, set |
Partial or add-on | Partial or add-on Through JavaScript | Supported DOM | Partial or add-on XSLT | Partial or add-on |
See PDF header and footer generation and preventing widows and orphans.
Fonts and international text
| Feature | PD4ML | iText + pdfHTML | PDFreactor | Aspose.HTML Java | BFO Publisher / RG | OpenHTMLtoPDF |
|---|---|---|---|---|---|---|
| TrueType and OpenType embedding with subsetting | Supported Fonts indexed ahead of time | Supported | Supported | Supported | Supported Including variable fonts | Supported |
| CFF OpenType (.otf) subsetting | Supported 4.2 | Supported | Supported | Not verified | Supported | Not verified |
| Kerning and ligatures | Supported | Partial or add-on pdfCalligraph add-on | Supported | Not verified | Supported | Partial or add-on |
| Arabic and Hebrew shaping, bidi | Supported | Partial or add-on pdfCalligraph add-on | Supported | Not verified | Supported | Partial or add-on ICU4J plugin |
| Indic and South-East Asian scripts | Supported Shaped without extra settings 4.2 | Partial or add-on pdfCalligraph add-on | Supported | Not verified | Supported | Partial or add-on |
| Chinese, Japanese, Korean | Supported | Supported | Supported | Supported | Supported | Supported |
Details: configuring PDF fonts.
Security, signatures and PDF post-processing
Every PD4ML edition, including STD, includes the PDF post-processing toolkit.
| Feature | PD4ML | iText + pdfHTML | PDFreactor | Aspose.HTML Java | BFO Publisher / RG | OpenHTMLtoPDF |
|---|---|---|---|---|---|---|
| Encryption and permissions | Supported RC4 40/128-bit, AES-128/256 | Supported | Supported | Partial or add-on Through Aspose.PDF | Supported | Partial or add-on Through PDFBox |
| Digital signatures | Supported PKCS#12, PKCS#11, HSM, cloud KMS, RFC 3161 timestamps, PAdES-LT/LTV | Supported | Supported | Partial or add-on Through Aspose.PDF | Supported PKCS#11, cloud HSM | Not supported |
| Merge PDFs | Supported Keeps accessibility tags consistent | Supported | Supported | Partial or add-on Through Aspose.PDF | Supported | Not supported |
| Optimize file size | Supported | Partial or add-on pdfOptimizer add-on | Not verified | Partial or add-on Through Aspose.PDF | Not verified | Not supported |
| XFDF import and export | Supported ISO 19444-1 | Supported | Not supported | Not supported | Not verified | Not supported |
| Low-level PDF object editing | Supported COS object model with incremental updates | Supported | Not supported | Not supported | Supported | Partial or add-on PDFBox |
See PD4ML PDF Signing, PDF Merge, PDF Optimizer and PDF COS.
Tools, APIs and integrations
| Feature | PD4ML | iText + pdfHTML | PDFreactor | Aspose.HTML Java | BFO Publisher / RG | OpenHTMLtoPDF |
|---|---|---|---|---|---|---|
| Command-line tool | Supported Pd4Cmd plus signing, merge, optimize, COS and XFDF tools | Not supported | Supported | Not supported | Supported | Not supported |
| Desktop previewer | Supported PD4Browser with Fonts Tool | Partial or add-on RUPS (PDF inspector) | Not supported | Not supported | Supported Web interface | Not supported |
| Web service and Docker image | Not supported | Not supported | Supported REST and SOAP, official image | Partial or add-on Docker sample | Supported HTTP and WebSocket, image | Not supported |
| JSP and servlet integration | Supported Tag library for javax and Jakarta EE 9+ | Not supported | Not supported | Not supported | Partial or add-on | Not supported |
| Languages | Java, Python, PHP, .NET, Node.js, Ruby | Java, .NET | Java, .NET, PHP, Python, Ruby, Perl, Node.js | Java | Java | Java |
| Custom resource loading | Supported Custom URL schemes (database, CMS) | Supported | Not verified | Supported | Not verified | Supported |
| IBM Notes/Domino | Supported | Not supported | Not supported | Not supported | Not supported | Not supported |
Start with Pd4Cmd, PD4Browser, PD4ML for Python or using PD4ML with Apache Maven.
PD4ML vs. iText pdfHTML
iText is a broad PDF toolkit, and pdfHTML is its HTML add-on: HTML becomes iText layout objects, which suits teams that already build PDFs with iText's API. Commercial use without publishing your own source code requires a commercial license, priced per customer as a subscription. PD4ML is a single engine for HTML and CSS with a perpetual license, writes DOCX and RTF from the same layout, ships PDF/UA-2 and ZUGFeRD presets, and includes signing, merging and optimization in every edition. Complex-script shaping and PDF optimization, which are separate add-ons in iText, are part of PD4ML.
PD4ML vs. PDFreactor
PDFreactor runs JavaScript before layout and implements CSS Paged Media in depth, which helps with chart libraries, Canvas and print-production features such as PDF/X. It is sold as an annual subscription. PD4ML has no script engine and no PDF/X, but costs less than one month of a PDFreactor Pro subscription for a single license, never expires, adds DOCX and RTF output, and offers PDF/UA-2 and e-invoice presets. If your templates do not depend on client-side JavaScript, PD4ML covers the same reports, invoices and catalogues.
PD4ML vs. Aspose.HTML for Java
Aspose.HTML is an HTML processing toolkit: a W3C DOM, scripting and conversion to many formats, with advanced PDF/A and PDF/UA work typically handled by Aspose.PDF. PD4ML is print-focused: deterministic pagination, page headers and footers, footnotes, tables of contents, fillable forms and PDF/UA tagging are built into the engine, and PD4ML 4.2 adds its own DOM API and layout read-back.
PD4ML vs. BFO Publisher and Report Generator
BFO Publisher is architecturally closest to PD4ML: pure Java, its own CSS engine, a command-line tool and a web service, with strong PDF/UA and PDF/X support. It is licensed per server. PD4ML's single, site and enterprise licenses cover unlimited servers at the site and enterprise levels, and PD4ML adds DOCX and RTF output, ZUGFeRD presets and bindings for Python, PHP, .NET, Node.js and Ruby. BFO Report Generator renders its own XML report format rather than general HTML.
PD4ML vs. OpenHTMLtoPDF
OpenHTMLtoPDF is free under the LGPL and a good fit for simple XHTML with CSS 2.1. It has no Flexbox or CSS Grid, no DOCX or RTF output and no digital signatures, and it is maintained by a community fork. PD4ML adds modern CSS layout, office formats, e-invoices, signatures and commercial support, starting at €100.
When PD4ML is not the right choice
- Your templates need JavaScript to produce their content, for example charts drawn on a
<canvas>at load time. PD4ML has no script engine; render such charts as SVG or images on the server instead. - You need PDF/X or spot colours for commercial printing.
- You want a ready-made HTTP conversion service with an official Docker image rather than a library.
- You need WebP images: PD4ML decodes images through Java ImageIO (JPEG, PNG, GIF, BMP).
Frequently asked questions
What is the best Java library for converting HTML to PDF?
It depends on your templates and standards. For server-side reports, invoices and documents written in HTML and CSS without client-side JavaScript, PD4ML offers modern CSS layout, PDF/A, PDF/UA and ZUGFeRD with a perpetual license. If templates depend on JavaScript, PDFreactor or a headless browser fit better; for a free option with simple XHTML, OpenHTMLtoPDF.
Is PD4ML a good alternative to iText pdfHTML?
Yes, for HTML-to-PDF conversion. PD4ML converts HTML and CSS directly, produces PDF/A, PDF/UA and ZUGFeRD, writes DOCX and RTF, and includes signing and merging, under a one-time license instead of an AGPL or subscription license.
Does PD4ML support CSS Flexbox and CSS Grid?
Yes. Flexbox and CSS Grid are real layout modes in PD4ML. PD4ML 4.2 rewrites the Grid implementation to the CSS Grid specification, including template areas, line names and dense placement.
Can PD4ML create accessible PDF/UA documents?
Yes. The PD4ML UA edition writes tagged PDF/UA-1, and PDF/UA-2 on PDF 2.0, and can combine PDF/UA with the accessible PDF/A levels 1a, 2a and 3a.
Can PD4ML convert HTML to Word (DOCX)?
Yes. The DMS and UA editions convert HTML and CSS to DOCX, and the PRO edition and higher to RTF, from the same layout used for the PDF.
Does PD4ML execute JavaScript?
No. PD4ML lays out HTML and CSS without a script engine, which keeps conversions fast and deterministic. Content produced by scripts, such as charts on a canvas, should be rendered as SVG or images before conversion.
How much does PD4ML cost compared with iText and PDFreactor?
A PD4ML single license starts at €100 and is perpetual. Unlimited site licenses cost €1,600 to €3,200 once. PDFreactor Pro lists at $1,908 per year, and iText commercial licenses are quoted per customer as subscriptions.
Which PD4ML edition do I need for ZUGFeRD or Factur-X invoices?
The DMS edition produces ZUGFeRD and Factur-X invoices on PDF/A-3b. For accessible invoices on PDF/A-3a, use the UA edition.
Try PD4ML
Every PD4ML edition can be evaluated with all features enabled; unlicensed output carries a watermark. Download PD4ML, follow the Programmer's Manual and the usage examples, and compare the result with your current library on your own templates. When you are ready, choose a license.
Product names are trademarks of their respective owners. Competitor capabilities and prices are taken from public sources as of November 2026 and may have changed; corrections are welcome through PD4ML support.