Building a Free Online PDF Converter with Next.js: What I Learned

Basit Chingisi — Fri, 26 Jun 2026 07:28:13 +0000

PDF files are everywhere. Developers, students, businesses, and creators use them every day for documents, reports, invoices, and forms.

However, working with PDFs on the web is not always simple. Many users still need to download software just to convert a file from PDF to Word, JPG, or another format.

I wanted to solve this problem by building a free online PDF converter that works directly in the browser.

The goal was simple:

Create a fast, easy-to-use tool where users can upload a PDF, convert it, and download the result without installing anything.

Why Build a Browser-Based PDF Tool?

Traditional PDF software often comes with problems:

Requires installation
Takes up storage space
Can be slow on older devices
Some tools require paid subscriptions

A web-based solution removes these barriers.

With modern web technologies, developers can now build powerful file processing tools that run smoothly in the browser.

I wanted to solve this problem by building a free online PDF converter that works directly in the browser.

The tool is available on Slaytic Tools:

The Technology Stack

For this project, I used a modern web stack:

Next.js for the application framework
React for the user interface
JavaScript for functionality
Browser APIs for file handling
Server-side processing where needed

Next.js makes it easier to create fast pages, manage routing, and optimize performance.

Handling PDF Files on the Web

PDF conversion is challenging because PDFs are not just simple text files.

A PDF can contain:

Text
Images
Fonts
Layout information
Metadata
Embedded objects

A good converter needs to preserve the original structure as much as possible.

The workflow usually looks like this:

User uploads a PDF file
The application validates the file
The conversion process starts
The converted file is generated
The user downloads the result

Keeping this process simple improves the user experience.

Important Performance Considerations

File tools need to feel fast.

Some improvements that matter:

Client-Side Processing

Whenever possible, processing files directly in the browser reduces server load and improves privacy.

Users feel more comfortable when their files are not unnecessarily uploaded.

File Size Limits

Large files can slow down browsers and servers.

Adding clear file size limits helps prevent performance problems.

Loading States

Users should always know what is happening.

A progress indicator or loading message helps avoid confusion during conversion.

Security Considerations

File upload tools need proper security practices.

Important things to consider:

Validate uploaded file types
Limit file sizes
Remove temporary files after processing
Prevent malicious uploads
Avoid storing user files unnecessarily

Security is especially important when handling private documents.

Making the Tool User-Friendly

A good tool is not only about technology.

The user experience matters.

A simple flow works best:

Upload file
Choose conversion type
Convert
Download

No complicated settings. No unnecessary steps.

SEO and Discoverability for Tool Websites

Building the tool is only one part.

People need to find it.

For a PDF converter, useful content can include:

How to convert PDF to Word
How to reduce PDF size
Best free PDF tools
PDF tips and tutorials

Helpful content allows search engines and AI systems to better understand what the tool does.

What I Learned Building a PDF Tool

Creating online tools looks simple from the outside, but there are many small details involved.

The biggest lessons:

Performance matters
Simplicity improves conversions
Security cannot be ignored
Good content helps users discover the product

A useful tool solves a real problem.

That is the main reason I built Slaytic Tools, a collection of free online utilities designed to make everyday tasks easier.

If you are building a web-based tool, focus on solving one clear problem and make the experience as simple as possible.

webdevelopment #nextjs #javascript #pdf #opensource

Frontend Basics: Mastering HTML and CSS

Basit Chingisi — Mon, 30 Dec 2024 07:13:12 +0000

HTML, short for HyperText Markup Language, is the foundation of every website. It structures and organizes the layout of a webpage, acting as the building block for all web creations. On the other hand, CSS (Cascading Style Sheets) focuses on styling, making web pages look attractive and visually appealing. While they serve different purposes, HTML and CSS work closely together and are often used hand-in-hand.

Think of it like this: HTML builds the skeleton of a webpage, while CSS adds the flesh, giving it life and beauty. HTML handles the structure and content, while CSS takes care of the design and layout. However, HTML can be a bit rigid when it comes to making changes, whereas CSS allows for more flexibility, making it easier to tweak and adjust styles.

Because of their interdependence, mastering both HTML and CSS is essential for creating great websites. However, as web development evolves, many programmers are moving towards more dynamic tools like React JS. React is a modern frontend framework that allows for advanced structuring and interactive designs. While it still incorporates some HTML elements, it’s not as reliant on HTML as CSS is.

Having worked on projects using only HTML, CSS, and a bit of JavaScript, I’m excited about transitioning to React JS. I look forward to exploring its capabilities further during HNG’s internship 11!

DEV Community: Basit Chingisi