From Foxit SDK to PDFluent

Foxit requires per-seat licensing, ships native C++ binaries, and bundles DLL dependencies. PDFluent is a Rust crate with published pricing, no native DLLs, and a self-serve trial.

Migrating from Foxit SDK to PDFluent. Install with cargo add pdfluent

Migration steps

1

Remove the Foxit native binaries

Foxit ships platform-specific DLLs or shared libraries that must travel with your application. PDFluent is a single Rust crate — cargo add pdfluent, and Cargo fetches and compiles it. No DLL to distribute, no shared library to load at runtime.

Foxit SDK (before)
// C++ — Foxit SDK initialization
#include "include/fpdfview.h"

// fpdfview.dll / libfpdfview.so must be present at runtime
FPDF_InitLibrary();
FPDF_DOCUMENT doc = FPDF_LoadDocument("invoice.pdf", nullptr);
if (!doc) {
    // handle load failure
}
PDFluent (after)
// Rust — PDFluent, no native library required
use pdfluent::Document;

let doc = Document::open("invoice.pdf")?;
2

Replace the Foxit license key with a PDFluent license

Foxit requires a license key passed at initialization time, and licensing is per seat. PDFluent uses a single license file with transparent published tiers. Replace the Foxit key initialization with a one-line PDFluent license call, or rely on the 30-day trial mode for evaluation.

Foxit SDK (before)
// Foxit — license key required before any API use
FPDF_InitLibraryWithConfig(&config);
// License key must match purchased seat count
const char* key = "YOUR_FOXIT_LICENSE_KEY";
FPDF_UnlockDDS(key, (int)strlen(key));
PDFluent (after)
// PDFluent — no initialization call needed during trial
// For production, set once at startup:
pdfluent::set_license_key("YOUR_PDFLUENT_KEY");
3

Map Foxit document operations to PDFluent equivalents

Foxit operations map closely to PDFluent. Open a document, access pages by index, extract text or fill forms, and save. The main difference is error handling: Foxit returns null or numeric error codes; PDFluent returns Result types that the compiler forces you to handle.

Foxit SDK (before)
FPDF_PAGE page = FPDF_LoadPage(doc, 0);
FPDF_TEXTPAGE text_page = FPDFText_LoadPage(page);
int char_count = FPDFText_CountChars(text_page);

char16_t buf[4096];
FPDFText_GetText(text_page, 0, char_count, buf);

FPDFText_ClosePage(text_page);
FPDF_ClosePage(page);
FPDF_CloseDocument(doc);
PDFluent (after)
let text = doc.page(0)?.extract_text()?;
println!("{}", text);
// All resources freed when doc goes out of scope

Things to watch out for

  • !Foxit page indexes are 0-based, matching PDFluent's 0-based indexing. No page number adjustments are needed.
  • !Foxit's per-seat licensing means adding a server replica requires purchasing an additional seat. PDFluent pricing is per deployment tier, not per seat.
  • !Foxit ships separate SDKs for different platforms (Windows, Linux, macOS, iOS, Android). PDFluent builds from one codebase for all targets, including WASM.
  • !If you use Foxit's annotation APIs, verify PDFluent's annotation support covers your use case before migrating.

Frequently asked questions