Comparison · PSPDFKit / Nutrient alternative
The server-side
PSPDFKit alternative
PSPDFKit, now Nutrient, is a leader in document viewers, annotation and eSign user interfaces across web and mobile. rust-pdf is not that. It is the server-side alternative for the other half of the job: generating and signing compliant PDFs. Where they overlap, rust-pdf adds PAdES B-LTA, Factur-X, nine languages and flat published pricing. Here is the honest line between them.
Different jobs, one overlap
PSPDFKit is bought to put a document viewer, annotator or editor in front of users, in the browser, on iOS and Android, with eSign flows and AI document processing. That is its home turf and rust-pdf does not compete there. If a viewer is what you need, PSPDFKit is the right tool.
The two products overlap on the server side: producing PDFs, signing them, validating PDF/A and encrypting. That is the whole of what rust-pdf does, and it does it in nine languages, fully offline, with deeper signature leveling and e-invoicing. This page compares only that overlap, fairly.
Where rust-pdf is different on the server
Four contrasts on the generation and signing work the two share.
Transparent flat pricing
Published prices, free then 1,500 and 3,000 USD per year, versus quote-only, contact-sales pricing where a three-year commitment is common.
PAdES B-LTA and Factur-X
rust-pdf signs through long-term-archival B-LTA and produces ZUGFeRD and Factur-X invoices. PSPDFKit's signing stops at B-LT and it has no e-invoicing.
Nine server languages
Including PHP, Ruby, Go and Delphi, which PSPDFKit's server SDKs do not cover, all from one core with identical output.
Fully offline and deterministic
Runs entirely on your servers with no cloud dependency or telemetry, and the same input always produces byte-identical output.
rust-pdf vs PSPDFKit / Nutrient
Compared on the server-side overlap. Where PSPDFKit leads, including the viewer it is built for, the table says so.
| Capability | PSPDFKit / Nutrient | rust-pdf |
|---|---|---|
| Primary purpose | Viewing, annotation and eSign UIs plus Document Engine | Server-side PDF generation, signing and compliance |
| Platforms and languages | Web, iOS, Android, Flutter, React Native, .NET, plus server SDKs (.NET, Java, Python, Node) | Nine bindings: Python, C#, Go, PHP, Ruby, Node, Java, Delphi, Swift |
| Interactive viewer and annotation UI | Yes, best in class | No, out of scope |
| PDF/A | Validate and convert | Generate 1b to 3a |
| PAdES signatures | B-B, B-T, B-LT (B-LTA not supported) | B-B, B-LT, B-LTA + LTV |
| PDF/UA accessibility | Yes | Yes (UA-1) |
| Encryption | AES-128, AES-256 | RC4, AES-128, AES-256 |
| ZUGFeRD / Factur-X | No | Yes |
| Deployment | SDK plus cloud Document Engine | Fully on-prem, offline, deterministic |
| Pricing model | Quote-only, multi-year commitment common | Published: free, 1,500, 3,000 USD, OEM |
Where PSPDFKit leads honestly: the interactive viewer, annotation and eSign experience across web, mobile and desktop, plus OCR and AI document processing, none of which rust-pdf offers. Pricing estimates for PSPDFKit are from independent third parties, since its own pricing is not published.
Pricing, side by side
The clearest practical difference for a procurement team.
PSPDFKit / Nutrient
- Quote-only. Pricing is not published; you contact sales.
- Priced by component and deployment model, typically annual or multi-year, with a three-year commitment being common.
- Independent third-party estimates put it in the tens of thousands of dollars per year. There is no free tier, only a 30-day watermarked trial.
rust-pdf
- Published, flat per-application annual pricing.
- Free Community, Pro at 1,500 USD per year, Enterprise at 3,000 USD per year, plus OEM and Site licensing.
- Activated by an offline token, no metering, no lock-in beyond the annual term.
When PSPDFKit is the right choice
Pick PSPDFKit / Nutrient if any of these is true
You need to embed a document viewer, annotator or editor in a web or mobile app, you want client-side rendering, or you want a hosted Document Engine, OCR or AI document processing. That is its core strength, and rust-pdf does not compete there.
Pick rust-pdf if any of these is true
Your need is server-side generation and signing of compliant documents: PDF/A, PAdES through B-LTA, AES-256, PDF/UA and Factur-X, in languages including PHP, Ruby, Go and Delphi, fully offline, at a transparent flat price. For producing documents rather than displaying them, rust-pdf is the simpler, cheaper fit.
Factur-X e-invoices, which PSPDFKit does not offer
One call embeds the EN 16931 invoice XML, switches the document to PDF/A-3, and writes the Factur-X identification into the metadata. The output is checked by veraPDF, in four of the nine rust-pdf languages.
# pip install rustpdf
import rustpdf
xml = open("invoice.xml", "rb").read() # EN 16931 Cross-Industry Invoice
with rustpdf.Document() as doc:
doc.facturx(xml, rustpdf.FacturxProfile.EN16931) # -> PDF/A-3 + Factur-X
doc.set_info(title="Invoice INV-2026-0042")
f = doc.add_font_file("Roboto-Regular.ttf")
doc.add_page()
doc.show_text(f, 22, 72, 760, "Invoice INV-2026-0042")
doc.save("invoice_facturx.pdf") # veraPDF-valid hybrid invoice// dotnet add package RustPdf
using RustPdf;
byte[] xml = File.ReadAllBytes("invoice.xml"); // EN 16931 CII
using var doc = new Document();
doc.Facturx(xml, FacturxProfile.En16931) // -> PDF/A-3 + Factur-X
.SetInfo(title: "Invoice INV-2026-0042");
int f = doc.AddFontFile("Roboto-Regular.ttf");
doc.AddPage();
doc.ShowText(f, 22, 72, 760, "Invoice INV-2026-0042");
byte[] bytes = doc.ToBytes(); // hybrid invoice// go get github.com/rustpdf/rustpdf-go@latest
xml, _ := os.ReadFile("invoice.xml") // EN 16931 CII
doc, _ := rustpdf.New()
defer doc.Close()
doc.Facturx(xml, rustpdf.FacturxEN16931) // -> PDF/A-3 + Factur-X
doc.SetInfo(rustpdf.Info{Title: "Invoice INV-2026-0042"})
f, _ := doc.AddFontFile("Roboto-Regular.ttf")
doc.AddPage()
doc.ShowText(f, 22, 72, 760, "Invoice INV-2026-0042", 0)
data, _ := doc.ToBytes() // hybrid invoice// npm install rustpdf
const { Document, FacturxProfile } = require("rustpdf");
const fs = require("fs");
const xml = fs.readFileSync("invoice.xml"); // EN 16931 CII
const doc = new Document();
doc.facturx(xml, FacturxProfile.EN16931) // -> PDF/A-3 + Factur-X
.setInfo({ title: "Invoice INV-2026-0042" });
const f = doc.addFontFile("Roboto-Regular.ttf");
doc.addPage();
doc.showText(f, 22, 72, 760, "Invoice INV-2026-0042");
const bytes = doc.toBytes(); // hybrid invoiceSee PAdES signatures through B-LTA, PDF/A and ZUGFeRD / Factur-X in the documentation.
PSPDFKit alternative FAQ
Is rust-pdf a replacement for PSPDFKit?
Only for the server-side generation and signing job. If you need an interactive PDF viewer, annotator or editor embedded in a web or mobile app, PSPDFKit, now Nutrient, is the right tool and rust-pdf does not provide that. The two overlap on producing, signing and validating compliant PDFs on the server, which is what this comparison covers.
Does rust-pdf render or display PDFs in the browser?
No. rust-pdf generates, signs, encrypts and processes PDFs on the server. It has no viewer or annotation user interface. Browser rendering and annotation are core PSPDFKit strengths.
What can rust-pdf do that PSPDFKit cannot?
rust-pdf signs at PAdES B-LTA, while PSPDFKit's signing stops at B-LT. rust-pdf also produces ZUGFeRD and Factur-X e-invoices, which PSPDFKit does not market, and it ships bindings for PHP, Ruby, Go and Delphi, which PSPDFKit's server SDKs do not cover.
How does rust-pdf pricing compare to PSPDFKit?
rust-pdf publishes flat per-application annual pricing: free Community, Pro at 1,500 USD per year, Enterprise at 3,000 USD per year, plus OEM and Site licensing. PSPDFKit pricing is quote-only, typically annual or multi-year with a three-year commitment being common. Independent third-party estimates put it in the tens of thousands of dollars per year.
Is rust-pdf fully on-premise?
Yes. rust-pdf runs entirely on your servers, offline, with no telemetry and deterministic, byte-identical output. PSPDFKit offers SDKs alongside cloud services such as its Document Engine and hosted APIs.
Does rust-pdf do OCR or AI document processing?
No. OCR and AI document processing are PSPDFKit strengths. rust-pdf focuses on standards-compliant generation, signing, encryption and text and image extraction.
Try rust-pdf on your server
Prototype for free, then license the corporate features when you ship. One core that generates, signs and validates compliant PDFs across nine languages, entirely on your own infrastructure.