---
title: "How to Build a Browser-Based PDF Crop Tool Using JavaScript"
url: https://daily.dev/posts/how-to-build-a-browser-based-pdf-crop-tool-using-javascript-g3xyckmya
source_url: https://www.freecodecamp.org/news/build-pdf-crop-tool-javascript
type: article
source: "freeCodeCamp"
author: "AllInOneTools"
published: 2026-06-13T11:27:34.033Z
updated: 2026-06-14T08:00:54.652Z
tags: ["javascript"]
reading_time: 10
upvotes: 15
comments: 2
language: en
---

> ## Documentation Index
> Fetch the complete documentation index at: https://daily.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# How to Build a Browser-Based PDF Crop Tool Using JavaScript

**[freeCodeCamp](https://daily.dev/sources/freecodecamp)** · [@allinonetools](https://daily.dev/allinonetools) · 10 min read · 15 upvotes · 2 comments

## Summary

A step-by-step guide to building a browser-based PDF crop tool using JavaScript and the pdf-lib library. Covers uploading PDFs, rendering page previews, defining crop areas visually, applying crop coordinates to selected pages, generating the cropped PDF, and downloading the result — all without a backend server. Includes code snippets for reading crop coordinates, supporting predefined page ratios (e.g., A4), selecting page ranges, validating inputs, and common mistakes to avoid.

## Full article

daily.dev links to this article rather than hosting it. Read it at the original source: <https://www.freecodecamp.org/news/build-pdf-crop-tool-javascript>

## Community discussion

Top comments from developers on daily.dev.

**@springtofigh** · 1 upvotes

> Awesome tutorial👌

## Similar posts on daily.dev

- [How to Build a Browser-Based PDF Resizer Using JavaScript](https://daily.dev/posts/how-to-build-a-browser-based-pdf-resizer-using-javascript-aqogolius) · freeCodeCamp · 7 upvotes · 0 comments
- [How to Build a Browser-Based PDF Margin Tool Using JavaScript](https://daily.dev/posts/how-to-build-a-browser-based-pdf-margin-tool-using-javascript-mpbzmfswj) · freeCodeCamp · 2 upvotes · 0 comments
- [How to Build a Browser-Based PDF Image Extractor Using JavaScript](https://daily.dev/posts/how-to-build-a-browser-based-pdf-image-extractor-using-javascript-pf87bj3dy) · freeCodeCamp · 2 upvotes · 0 comments
- [How to Build a Browser-Based PDF Redaction Tool Using JavaScript](https://daily.dev/posts/how-to-build-a-browser-based-pdf-redaction-tool-using-javascript-jti1xfs3t) · freeCodeCamp · 1 upvotes · 1 comments
- [How to Build a Browser-Based PDF Organizer Tool Using JavaScript](https://daily.dev/posts/how-to-build-a-browser-based-pdf-organizer-tool-using-javascript-9wolfwjgv) · freeCodeCamp · 2 upvotes · 0 comments

---

Tags: [#javascript](https://daily.dev/tags/javascript)

[View this post on daily.dev](https://daily.dev/posts/how-to-build-a-browser-based-pdf-crop-tool-using-javascript-g3xyckmya)