DEV Community: Zengkkj

Crow Docs v22: Fixing 12 bugs across an offline-first PDF toolkit

Zengkkj — Thu, 02 Apr 2026 22:46:37 +0000

What is Crow Docs?

Crow Docs is a free, open-source, browser-based document toolkit. Merge, split, compress, sign, translate, OCR, compare, booklet, metadata editing, Markdown-to-slides, image-to-PDF, PDF-to-audio, PDF-to-PPTX — it does a lot.

The key detail: everything runs 100% client-side. No file uploads. No server processing. Your documents never leave your device. It's a PWA, so it works offline too.

The email that started everything
A user wrote in with two issues: "the PPTX export doesn't open in PowerPoint" and "GIFs in my PDF don't animate."

Fair feedback. But instead of patching just those two things, I decided to audit every tool in the app. What I found was humbling — 12 bugs across the entire toolkit, some hiding in plain sight for months.

The 12 bugs (and why they existed)

PDF to PPTX wouldn't open in PowerPoint — Google Slides is forgiving about missing OOXML structure. PowerPoint is not. Added proper theme, clrMap, txStyles, grpSpPr transforms, and docProps.
QR codes wouldn't scan — Custom inline QR encoder had subtle bugs. Replaced with the battle-tested qrcode-generator library.
Compare PDFs showed NaN — ImageData dimensions mismatch when PDFs had different page sizes. Fixed by normalizing to same-size canvas.
Booklet page ordering was wrong — Saddle-stitch imposition algorithm had incorrect formula for inner sheets. Corrected: outerLeft = total-1-s*2, outerRight = s*2, innerLeft = s*2+1, innerRight = total-2-s*2.
Markdown to Slides splitting failed — Regex didn't handle whitespace around --- or Windows \r\n line endings.
Translate PDF lost paragraphs — join(' ') instead of join('\n'). One character, all paragraphs gone.
PDF metadata keywords stored incorrectly — Saved as single-element array instead of splitting by comma.
Sign PDF crash — No null check on canvas element before drawing.
Organize PDF used generic filename — Now preserves the original filename.
GIF in PDF — no warning — PDFs don't support animation. Added toast notification explaining the limitation.
OCR errors showed "undefined" — Six catch blocks used e.message without fallback. Fixed with e?.message || String(e).
Header/footer regex typo — /^Página?/ matched "Págin" instead of "Página". Fixed to /^P[aá]gina/i.

Lessons learned
PowerPoint doesn't forgive. Google Slides will render a half-valid PPTX. PowerPoint will reject it. Test against the strictest consumer.

Users find what tests don't. A real person trying to open your file in their specific environment — that's where edge cases live.

Self-hosting dependencies pays off. Every library lives in /libs/. No CDN calls. The offline story is bulletproof because there are zero external runtime requests.

Tech stack
Vanilla JS. No frameworks, no build step. The heavy lifting comes from: pdf-lib, jsPDF, PDF.js, Tesseract.js, JSZip, mammoth, docx, and qrcode-generator.

Try it, break it, tell me

Crow Docs Evolving: Stability, UX, and a New Community Channel 🚀

Zengkkj — Mon, 30 Mar 2026 22:02:41 +0000

Crow Docs Evolving: Stability, UX, and a New Community Channel 🚀
Hi everyone!

I’m dropping by to share a general update on the Crow Docs project. The focus of the latest updates was ensuring a solid foundation, fluid navigation, and—most importantly—opening a direct channel to hear from those using the tool.

For those who aren’t familiar, Crow Docs is a suite of PDF and OCR tools that runs 100% client-side, prioritizing privacy above all else (no server uploads, ever!).

🛠️ What’s New?
Interface Refinement: We’ve implemented UX improvements and optimized loading speeds for a much smoother experience. Less friction, more productivity.

Deep Bug Squashing: We did a thorough "fine-tooth comb" sweep! We fixed instabilities and minor rendering glitches that were popping up in specific browser environments.

Suggestions Box: We now have an official channel! Want a new feature or found something weird? Your feedback now has a dedicated home at the bottom of the page.

Project Support: I've added a section for anyone who wants to support the development and help keep the project's infrastructure standing.

💡 Why the Community Focus?
This project is driven by real-world usage. Adding the Suggestion and Support buttons at the footer was the best way I found to turn Crow Docs into something built by many hands.

🔗 Explore it now:
If you need fast, secure, and privacy-focused PDF tools, take a look:

👉 crowdocs.com.br

What feature would you like to see in a 100% browser-based document tool? Let me know in the comments or use the new suggestion box on the site!

Crow Docs v2.0 — High-Speed OCR, Markdown to Slides, and 100% Client-Side Privacy 🚀

Zengkkj — Sat, 28 Mar 2026 23:52:24 +0000

Crow Docs v2.0 — New Tools, Supercharged OCR, and Bug Fixes

Hey everyone!

I'm excited to share a massive update for Crow Docs (v2.0). If you're looking for a document utility suite that actually respects your data, this is for you.

The core philosophy remains: 100% Client-Side Processing.
No uploads, no servers, no registration. Your documents never leave your computer. 🔒

Here is what’s new in this version:

🚀 New Features & Improvements

🎨 Markdown → Slides (New!)

Convert your Markdown files into professional PDF presentations instantly.

Customization: Themes (Dark, Light, Blue, Green, Gradient).
Layouts: 16:9 or 4:3 aspect ratios.
Readability: Fully configurable font sizes.

🔍 Supercharged OCR

We’ve overhauled the character recognition engine:

Parallel Processing: Faster multi-page recognition.
Smart Auto-Rotation: Automatically detects and corrects page orientation.
Global Language Support: New support for Japanese, Korean, Chinese, Arabic, Russian, Hindi, Turkish, Polish, Dutch, and multi-language combinations.

📄 Improved Workflow

DOCX Preview: View your Word documents directly in the browser before converting to PDF.
Progress Bars with ETA: Real-time tracking so you know exactly when your task will be finished.
File Validation: Instant validation of file types and sizes before processing starts.

🐛 Bug Fixes & Stability

We’ve addressed several key issues to make the experience smoother:

PDF → Word: Fixed the bug that limited conversions to the first page. Large documents now convert completely.
Word → PDF (Academic Standards): Fixed the ABNT NBR 14724 formatting issues. Margins (3/2/3/2 cm), Arial 12pt, 1.5 spacing, and 1.25cm paragraph indents are now perfectly applied.
Navigation: Fixed scroll hijacking. When returning from a tool, the site now keeps your exact scroll position on the main page.

🎨 New Visual Identity

Crow Docs has a fresh new look:

Exclusive Logo: A new "Crow" icon that adapts to your theme (White for Dark Mode, Black for Light Mode).
Consistent Branding: New favicon and OpenGraph images for better social media sharing.

🔗 Try it out

The project is free and built for the community. If you need to handle sensitive documents without the risk of cloud uploads, check it out:

👉 crowdocs.com.br

What do you think of these new features? If you have any suggestions for future tools or improvements for the "Crow", let me know in the comments! 👇

🚀 Crow Docs Update: Client-side PDF processing is getting even more powerful

Zengkkj — Mon, 23 Mar 2026 19:24:30 +0000

Hello, Dev Community!

I’ve been working on Crow Docs, a "Swiss Army Knife" for PDF manipulation that runs entirely in your browser. Today, I’m excited to share some major updates and a few technical challenges I've solved.

What is Crow Docs?
If you missed the previous posts, Crow Docs is an open-source alternative to tools like SmallPDF or ILovePDF. The main difference? Zero uploads. Everything happens on the client-side using the user's hardware. Your sensitive documents never leave your machine.

🆕 What’s New?
We’ve just integrated three high-demand features:

🎧 PDF to Audio (TTS): Using the Web Speech API to turn static documents into accessible "podcasts". Perfect for studying on the go.

📄 Resume Builder: A streamlined, schema-based generator to create clean, professional CVs without formatting headaches.

🌍 PDF Translator: Breaking language barriers by integrating translation logic directly into the document workflow.

🛠️ The Tech Stack & Challenges
Building these features without a backend for processing is a fun challenge. We are leveraging:

pdf-lib & pdf.js for core manipulation.

Web Workers to ensure the UI doesn't freeze during heavy processing.

Local Storage/IndexedDB for state management without tracking.

The biggest hurdle? Memory management. Processing a 100MB PDF strictly in RAM requires some creative "chunking" to keep the browser happy.

Why go Client-Side?
In an era of data breaches, privacy isn't just a feature; it's a requirement. By keeping the logic in the browser, we eliminate server costs (yay, free hosting!) and, more importantly, we guarantee user privacy by design.

Check it out here: https://crowdocs.com.br/

I’d love to hear your thoughts on the performance of these new tools. If you’re a fellow dev, what’s the most annoying thing you’ve faced when working with PDF libraries in JS?

I built a free PDF toolkit that runs 100% in your browser — no uploads, no sign-ups

Zengkkj — Sat, 21 Mar 2026 20:09:01 +0000

The Problem

We've all been there:

Need to merge a PDF → site asks you to create an account
Need to compress → limited to 2 free files
Need to sign → $15/month subscription
And worst of all: your sensitive documents get uploaded to unknown servers

I got tired of this and built something different.

Meet Crow Docs 🐦

A complete PDF toolkit with 25+ tools that runs entirely in your browser. Your files never leave your device.

🔗 crowdocs.com.br

What can it do?

🔗 Merge PDF — Combine multiple PDFs
✂️ Split PDF — Extract specific pages
🗜️ Compress PDF — Reduce file size
🖼️ JPG to PDF — Convert images
🔄 PDF to Image — Export pages as JPG/PNG
💧 Watermark — Add text or image watermarks
✍️ Sign PDF — Draw or type your signature
🔏 Redact PDF — Black out sensitive info
🔢 Page Numbers — Add numbering
🔒 Protect/Unlock PDF — Password management
📖 Create Booklet — Print-ready imposition
📝 PDF to Word/Excel — Convert formats
...and 10+ more tools

Why is it different?

Feature	Crow Docs	iLovePDF	SmallPDF	Adobe
Free	✅ Always	❌ Limited	❌ Limited	❌ Paid
No sign-up	✅	❌	❌	❌
No upload	✅	❌	❌	❌
Works offline	✅	❌	❌	❌
Privacy	✅ Local	☁️ Cloud	☁️ Cloud	☁️ Cloud

Tech Stack

Pure HTML/CSS/JS — single file application
pdf-lib — PDF manipulation
pdf.js — PDF rendering
jsPDF — PDF creation
Cloudflare Pages — hosting with global CDN
PWA — installable, works offline

Zero backend. Zero database. Zero tracking.

How it works

Everything is processed using JavaScript APIs directly in your browser:

You select a file → it stays on your device
JavaScript processes it locally using Canvas API + PDF libraries
You download the result → nothing was ever uploaded

It's that simple. No server needed.

What I learned building this

The browser is incredibly powerful for document processing
pdf-lib can handle most PDF operations without a server
Canvas API + pdf.js can render and manipulate PDF pages pixel by pixel
A single HTML file can replace dozens of SaaS tools
Privacy and functionality don't have to be opposites

Try it out

🔗 https://crowdocs.com.br

Available in English and Portuguese with automatic language detection.

I'd love your feedback! What tools would you like to see added?

Built with ❤️ and JavaScript. No servers were harmed in the making of this product.