DEV Community: Tooba

ScanFlow AI: Build a Private, Browser‑Native Document Scanner That Never Sends Your Data to the Cloud

Tooba — Sun, 24 May 2026 18:46:04 +0000

You’d never hand your passport, receipts, or signed contracts to a stranger on the street. So why do we keep trusting random cloud APIs with our most sensitive documents?

Today I’m introducing ScanFlow AI – a complete document processing pipeline that runs entirely in your browser. Scan, crop, enhance, OCR, and export to PDF, all without a single HTTP upload. Let’s dive into how it works and why you might want to build (or just use) something similar.

The Problem with “Smart” Scanner Apps

Most scanning apps or web services do this:

You capture an image (camera or upload).
It’s sent to a server for perspective correction, enhancement, or OCR.
The result is returned – and your private document now lives on someone else’s disk, often indefinitely.

Even with good privacy policies, the attack surface is huge. For developers, it also means server costs, scaling headaches, and compliance nightmares (GDPR, HIPAA, etc.).

ScanFlow AI solves this by moving everything to the client side.

What ScanFlow AI Does (All Local)

The tool gives you the same core experience as popular scanner apps:

Scanning – Live camera feed with edge detection & perspective correction.
Cropping – Manual or auto region selection.
Enhancing – Brightness, contrast, sharpness, noise reduction, and even binarisation.
OCR – Extracts text from any image (multiple languages).
PDF Export – One‑click PDF generation from the processed image + optional text overlay.

Everything happens inside your browser tab. No data leaves your device.

Under the Hood: Key Technologies

Here’s what makes local document processing practical in 2025:

Feature	How ScanFlow AI does it (client‑side)
Camera & canvas	`getUserMedia()` + `Canvas API`
Perspective correction	Custom math + `WebGL` shaders (or fallback JS)
Image enhancement	`Canvas` filters + WASM colour transforms
OCR	Tesseract.js – runs a full LSTM engine in a worker
PDF generation	`jspdf` + `canvas` to embed images/text
Performance	Web Workers + SharedArrayBuffer for memory efficiency

Example OCR snippet (simplified):

import { createWorker } from 'tesseract.js';

const worker = await createWorker('eng');
const { data: { text } } = await worker.recognize(croppedCanvas);
await worker.terminate();

console.log('Extracted text (local only):', text);

No API key, no network request – just a worker churning on your CPU.

Why “Hooked” Developers Love This Approach

Privacy by default – Users never question where their receipt or medical form went.
No backend costs – Your “server” is the user’s laptop. Scale to millions without paying for OCR API calls.
Offline‑capable – Service worker + Tesseract models cached once → full functionality without internet.
Compliance ready – Since data never leaves the client, you can skip DPIAs for cloud OCR.
Easy embedding – Drop ScanFlow AI into any web app (React, Vue, vanilla) as a Web Component.

Real‑World Use Cases

Enterprise portals – Employees scan ID cards or NDA pages without IT worrying about data leakage.
Healthcare dashboards – Patient records processed locally – no HIPAA cloud risk.
Progressive web apps – Offline document scanner for field workers (inspection reports, delivery proof).
Privacy‑first browser extensions – Integrate OCR into Gmail / Drive without sending your emails to a third party.

Demo & Try It Yourself

ScanFlow AI is live right now at:

👉 scanflowai.blogspot.com

Open your browser’s DevTools → Network tab. Capture a document, run OCR, export PDF. You’ll see **zero* requests to any server (except to load the app itself). That’s the hook.*

The Road Ahead

We’re adding:

More OCR languages (Japanese, Arabic, Hindi) via dynamic Tesseract model loading.
HDR‑like enhancement using WebGPU compute shaders.
PDF/A‑1b export for archival use.
End‑to‑end encrypted share (opt‑in, WebRTC‑based) so you can send scanned docs peer‑to‑peer.

All staying 100% local unless the user explicitly invites a peer.

Build Your Own or Just Use Ours

The entire ScanFlow AI core is available as an MIT‑licensed library – grab it from the repo link on the blog sidebar. Or, if you just want a tool that never phones home, bookmark the website.

Next time you need to scan a document, remember:
The most private server is the one that doesn’t exist.

Happy local scanning,

– ScanFlow AI Team

I built a PDF tool that never sees your documents (and no, it's not a subscription)

Tooba — Sun, 24 May 2026 10:22:16 +0000

Here's a scenario you probably know.

You need to convert a PDF to Word. You find a "free" online tool. You upload your document, wait a few seconds, and download the file.

Then you spend the next week wondering where your sensitive contract or personal resume just went.

Most online PDF tools work by uploading your file to a server. That means your document sits on someone else's computer, often without any guarantee of when or if it gets deleted. For anything containing personal data, financial info, or private work, that's a non-starter.

So I built a different kind of PDF tool.

Meet PDF Architect. It does two main things:

Converts PDFs to editable Word documents while preserving page breaks and formatting.
Turns static PDFs into interactive fillable forms.

But the important part is how it works. Everything happens directly in your browser. Your files never leave your device. There are no server uploads, no cloud processing, no temporary storage on some remote machine. Once you close the tab, the document is gone from memory.

This is possible because the tool uses client-side libraries like pdf-lib and PDF.js. The entire conversion engine runs locally, using your computer's own resources. This means:

Zero privacy risk.
No file size limits (your browser is the only constraint).
Works offline after the first page load.

The tool is completely free, with no signup, no watermarks, and no "premium" tier that secretly uploads your data.

You can try it here: PDF Architect

I built this because I was tired of workarounds that compromise privacy. If you regularly handle sensitive PDFs, give it a shot.

Two questions for you:

What's the one feature you wish PDF tools would stop charging for?
Do you currently use any client-side document tools?

Drop a comment. I'm actively building based on feedback.

I got tired of paying $10/month to remove image backgrounds – so I built it for free

Tooba — Sat, 23 May 2026 11:49:58 +0000

Let me guess.

You have been there.

You need to remove a white background from a product photo.
Or convert a WebP image to PNG because some random website won't accept it.
Or save a JPG as a smaller WebP for faster loading.

And every time, you end up on some tool that:

Asks for your email
Limits you to 3 free images
Then hits you with a "9.99 dollars per month Premium" screen

Yeah, no.

I built GreenConvert, a dead-simple, completely free tool that does two things really well.

What GreenConvert actually does

Image format conversion

WebP to PNG
WebP to JPG
PNG to WebP
JPG to WebP
PNG to JPG
JPG to PNG

Just upload. Click convert. Download. No signup.

Background removal (AI powered)

Remove white, solid, or complex backgrounds
Works on product photos, profile pictures, logos
Takes about 2 seconds per image
Download as transparent PNG

Real examples where I use this daily

Use case 1: Website product images
Before: Heavy WebP from Canva
After: Convert to JPG for Shopify

Use case 2: Discord emotes
Before: PNG with white box
After: Remove background to transparent PNG

Use case 3: Thumbnail for a blog post
Before: Random JPG
After: Convert to WebP for faster loading

Use case 4: Print a photo
Before: WebP (cannot print)
After: Convert to PNG or JPG

Why I built it instead of paying

I am a cheap developer. I refuse to pay subscription fees for simple image utilities.

So I:

Wrapped a free AI background removal model
Added format conversion using browser APIs
Hosted it on a free tier (Blogspot actually works fine for this)
Added zero limits, watermarks, or email gates

Try it right now

Green Convert
No account. No credit card. No "start your free trial" nonsense.

Two quick questions for you

What other image format should I add? (TIFF, BMP, GIF)
Would you use a bulk or batch version (convert 50 images at once)?

Drop a comment. I actually read them and build what people ask for.

P.S. Your wallet can stop bleeding now.