I Built a Free Invoice Generator, Resume Builder, and Cover Letter Generator That Don't Require Signup

Source: Dev.to

Introduction

A friend asked me to recommend a free invoice generator yesterday. I opened the first ten results on Google and they all did the same thing: a signup wall, email capture, or a watermark across the PDF unless you pay $12/month. Generating a PDF from form fields is a solved problem that somehow became a SaaS category.

So I built three of them in a day:

• Invoice Generator
• Resume Builder
• Cover Letter Generator

All three run entirely in your browser. No data leaves your device. No account needed. No watermarks.

Why Existing Tools Fail

I tried to find free invoice generators for a freelancer friend last month. Every single one either:

• Required signup
• Limited you to one template
• Added their branding to the PDF
• Was clearly a funnel for their SaaS product

The same story applies to resume builders: the free tier gives you one basic template, and the moment you want something that looks professional, you hit a paywall.

The thing is, generating a PDF from form data is not a hard problem. The browser has everything it needs. pdf-lib is an excellent open‑source library that creates PDFs entirely in JavaScript. There is genuinely no reason your invoice data needs to touch someone else’s server.

Architecture Overview

All three tools share a common PDF‑rendering layer and a template system inspired by PptPresentationMaker (the most complex tool on Kitmul). The architecture is straightforward:

1. React state holds the form data.
2. An HTML/CSS live preview updates on every keystroke.
3. When you click Download, a pdf-lib PDF is generated (in a Web Worker) and offered as a Blob URL.

Invoice Generator

The Invoice Generator was the most technically interesting of the three.

Templates

Six templates are available:

1. Clean
2. Modern
3. Classic
4. Bold
5. Minimal
6. Corporate

Each has distinct header layouts and colour schemes. You can upload your company logo; the tool resizes it client‑side using a “ element before embedding it in the PDF with embedPng().

Features

• Auto‑calculations: subtotals, percentage or fixed‑amount discounts, tax rates.
• Live preview updates instantly.
• Currency selector: supports twelve currencies with locale‑aware formatting via Intl.NumberFormat.
• Header layout calculation: dynamically computes header height (logo + business info + invoice details) so the coloured background shrinks or expands based on filled fields.

Table Rendering

pdf-lib has no native table concept, so I wrote a shared drawTable helper that:

• Computes row heights based on text wrapping
• Handles alternating row backgrounds
• Automatically breaks to a new page if the table overflows

This helper is now reusable across all three tools.

Resume Builder

The Resume Builder is the most complex tool (~900 lines).

Templates

Five templates are available:

1. Classic – single column, maximum ATS compatibility
2. Modern – coloured sidebar for contact info and skills
3. Professional – two‑column header
4. Minimal – lots of whitespace
5. Executive – bold accent underlines

Design Choices

• Only StandardFonts from pdf-lib (Helvetica & Helvetica‑Bold) are used.
  • Custom fonts look nicer but break Applicant Tracking Systems (ATS).
• Every template outputs real, selectable text drawn top‑to‑bottom, never images of text.
• Even the Modern template draws the main content first in reading order, so an ATS reads your experience before your contact details.

Functionality

• Sections are reorderable via drag‑and‑drop (e.g., move Experience above Education).
• You can add Certifications, Languages, Projects, etc.
• Each experience entry supports multiple bullet points with add/remove controls.
• Multi‑page PDFs are generated with proper page breaks that never split a section header from its content.

Cover Letter Generator

The Cover Letter Generator is the simplest of the three, but that’s intentional. A cover letter is a formatted business letter; formatting errors make you look sloppy.

Templates

Four templates are available:

1. Traditional – sender info top‑right (formal standard)
2. Modern – large name with a horizontal accent line
3. Professional – coloured header block
4. Simple – clean, minimal layout

All templates follow proper business‑letter conventions: sender info placement, date formatting, greeting, body paragraphs, and sign‑off.

Key Points

• No AI writes your letter. You write it; the tool formats it.
• Human‑written content in a clean layout stands out more than a GPT‑generated letter in a fancy design.

Privacy & Data Security

These three tools handle sensitive information:

• Invoices: business details, client names, financial data
• Resumes: employment history, contact information
• Cover letters: specific companies you’re applying to

Every alternative I tested (Zoho, Canva, Resume.io, Zety, etc.) sends this data to a server, requires an account, and stores the data under their privacy policies—often using it for “service improvement” (i.e., training models).

Browser‑based tools make privacy the default:

• No server to send data to.
• pdf-lib generates the PDF in a Web Worker.
• The browser creates a Blob URL for download, keeping everything local.

Conclusion

Generating PDFs from form data is a solved problem that doesn’t need to be locked behind a SaaS paywall. By leveraging pdf-lib and client‑side rendering, I created three free, privacy‑first tools:

• Invoice Generator – six professional templates, live calculations, logo embedding.
• Resume Builder – five ATS‑friendly templates, drag‑and‑drop sections, multi‑page support.
• Cover Letter Generator – four clean business‑letter templates, no AI, full control over content.

All run entirely in the browser, require no signup, no watermarks, and no data leaves your device. Feel free to try them out and share the links with anyone who needs a free, trustworthy document generator.

Download behavior
The download happens through a local anchor click. Your data exists in browser memory until you close the tab.

Tools

• Receipt Generator – the mirror of invoices, for the receiving side
• NDA Generator – simple template‑based legal documents
• Meeting Minutes Generator – structured notes to PDF

All follow the same pattern: form data → live preview → clean PDF.
The shared layout helpers make each new tool faster to build than the last.

If you’re a freelancer creating invoices, a job seeker polishing your resume, or anyone who needs a professional document without the signup dance, give these a try. They’re at kitmul.com alongside 400+ other free browser‑based tools.

Related tools

• PPT Presentation Maker
• Text to PDF
• PDF Merger
• Budget Planner
• Image to PDF

References

• pdf-lib: Create and modify PDFs in JavaScript
• Applicant Tracking System (Wikipedia)
• Intl.NumberFormat (MDN)
• US business letter format (Purdue OWL)
• How ATS parsers read resumes (Jobscan)