Executive Overview
PDF documents frequently contain sensitive legal contracts, financial disclosures, personal identification, and proprietary business documents. Processing PDFs on server-based converters exposes these files to cloud storage leaks.
Local PDF Manipulation Engine
CoolTools uses PDF-Lib and PDF.js web libraries to read raw PDF byte arrays locally. Pages are rearranged, extracted, or merged into new PDF documents entirely in browser memory.
// Local PDF Merging Architecture
import { PDFDocument } from 'pdf-lib';
const mergedPdf = await PDFDocument.create();
for (const bytes of pdfBytesArray) {
const pdf = await PDFDocument.load(bytes);
const pages = await mergedPdf.copyPages(pdf, pdf.getPageIndices());
pages.forEach((p) => mergedPdf.addPage(p));
}Memory Limits & Large Files
Browser tab memory allows processing PDFs up to several hundred megabytes. Files are processed in streaming chunks using JavaScript Uint8Arrays to maintain high performance.
Frequently Asked Questions
Yes. Since document bytes are parsed locally in browser memory, confidential files are never exposed to remote servers.
Supports PDF 1.3 through PDF 2.0 specifications including scanned and vector documents.