Creating professional PDF documents manually can be tedious, error-prone, and time-consuming. Whether it’s invoices, reports, contracts, or other business documents, teams spend valuable hours formatting, merging, and delivering files. CustomJS simplifies this process with a powerful PDF Generation API, allowing businesses to automate document creation, ensure consistency, and scale operations efficiently all without managing servers or writing complex backend code.
What is a PDF Generation API?
A PDF Generation API enables applications to create, modify, and manage PDF files programmatically. Instead of manually converting HTML or other document formats into PDFs, the API allows you to pass dynamic data and templates directly to CustomJS. The service then generates high-quality PDFs instantly, ready for download, email, or storage. This makes it ideal for automating invoices, generating client reports, creating proposals, or converting websites into printable PDFs.
Why Automate Document Creation?
Manual document creation is prone to mistakes. A single formatting error or missing client detail can lead to delays or dissatisfied customers. Automating this process ensures documents are always accurate, professionally formatted, and delivered on time. With CustomJS, businesses can handle hundreds or thousands of documents daily without increasing staffing or operational costs. Automation also frees your team to focus on growth-oriented tasks rather than repetitive administrative work.
How CustomJS Makes PDF Automation Easy
CustomJS combines serverless JavaScript with a robust PDF API to make automation simple. Using HTML templates, you can define the structure, layout, and branding of your documents. Dynamic data from your database, CRM, or forms is automatically merged into the template, producing professional, client-ready PDFs. Beyond simple PDF creation, the API also supports merging multiple PDFs, compressing files, extracting pages, and converting documents to PNG images all from a single workflow.
Step 1: Build Your Template
Start by creating an HTML template for your document. CustomJS supports dynamic placeholders, allowing you to inject variables like client information, transaction details, dates, or totals directly into the template. This ensures every generated PDF is consistent, branded, and formatted to your exact specifications.
Step 2: Connect Your Data
CustomJS seamlessly integrates with popular automation platforms such as Make.com, n8n, and any REST API-compatible service. This enables dynamic document generation without writing additional server-side code. Your PDF workflow can automatically pull records from Airtable, CRM systems, or databases and merge them into your template in real time.
Step 3: Generate and Merge PDFs
Once your template and data source are set up, the PDF Generation API handles the rest. You can generate PDFs individually, or batch process multiple documents simultaneously. Using CustomJS’s merge functionality, you can combine multiple HTML pages or separate PDFs into a single file, perfect for compiling invoices, contracts, or multi-page reports.
Example code snippet:
const { PDF_MERGE, HTML2PDF } = require('./utils');
let pages = [input.page1, input.page2, input.page3].filter(Boolean);
pages = await Promise.all(pages.map(i => HTML2PDF(i)));
return PDF_MERGE(pages);
This allows you to pass multiple HTML pages, generate PDFs for each, and merge them into a single file effortlessly.
Step 4: Convert, Compress, or Extract
CustomJS goes beyond PDF generation. You can convert PDFs to PNG images, compress PDFs by up to 70%, or extract specific pages for further use. These features make it easy to repurpose documents for marketing materials, client delivery, or internal reports, all without additional tools or software.
Step 5: Deliver and Automate
After generating your documents, you can automatically send them via email, save them to cloud storage, or trigger follow-up actions using Make.com or n8n workflows. CustomJS ensures your workflow remains serverless, fast, and flexible, eliminating the need for manual steps and reducing human error.
Affordable, Scalable, and Easy to Use
CustomJS provides 600 free PDF/API calls every month, scaling affordably from just $9 per month for 3,000+ documents. Unlike other PDF APIs, there’s no need to manage servers or complex setup. With support for JavaScript coding, integrations with Make.com and n8n, and a flexible REST API, CustomJS empowers businesses to build fully automated PDF workflows that are both cost-effective and highly reliable.
Get Started Today with CustomJS
Automate document creation with CustomJS and transform how your business handles PDFs. From invoices and reports to contracts and client documents, CustomJS provides a fast, affordable, and scalable solution for professional document workflows. Start generating PDFs for free, integrate with your favorite automation platform, and take the first step toward a truly paperless, automated workflow.
Start Free with CustomJS PDF API →
