1. Core Principle — 100% Local Processing

All Adawati tools (except only 3) are built on one strict principle: processing happens locally in the user's browser, and no files or data are sent to our servers. This is achieved using modern web technologies that run in the browser (Client-Side) without the need for a server:

• Modern JavaScript (ES2020+) — to execute the logic.
• WebAssembly (WASM) — to run heavy libraries (like OCR, FFmpeg) at near-native speed.
• Canvas API — to process images and video.
• Web Crypto API — for encryption and secure random number generation.
• Web Audio API — to process audio.
• Web Workers — to run heavy operations without freezing the UI.

2. OCR Tools (Extract Text from Images)

OCR tools convert images containing text into editable text. We use the Tesseract.js library (a WebAssembly port of Tesseract OCR) to run it locally in the browser.

How it works

• The Tesseract model (WASM) is loaded in the browser (~10 MB, cached).
• The image is passed to the OCR engine, which analyzes pixels and detects characters.
• The results (text + coordinates + confidence) are returned in the browser.
• The user can copy the text or download it as a file.

Tools in this category

image-to-text.php

Technology	Usage
Tesseract.js	OCR engine (WASM)
Canvas API	Read image pixels
Web Workers	Run OCR without freezing the UI
FileReader API	Read file locally

3. PDF Tools (16 Tools)

PDF tools are the largest and most diverse category on our site. They all rely on two core libraries: pdf.js (from Mozilla) to read PDFs, and pdf-lib to modify and create them. Both run fully locally.

General mechanism

• Reading: Files are opened using pdf.js, which converts them into viewable/renderable pages.
• Editing: pdf-lib is used to merge/split/rotate/delete/add pages and watermarks.
• Creation: jsPDF or pdf-lib is used to create a new PDF (from images or other pages).
• Conversion: Each page is drawn onto a Canvas then exported as an image, or converted to PowerPoint via PptxGenJS.

Tools in this category

mareg-pdf.php pdf-editor.php pdf-to-word.php protect-pdf.php rotate-pdf.php merge-pdf.php pdf-watermark.php split-pdf.php number-pdf-pages.php pdf-to-images.php delete-pdf-pages.php unlock-pdf.php compress-pdf.php pdf-to-powerpoint.php sign-pdf.php images-to-pdf.php

Tool	Core Technology
Merge, Split, Rotate, Delete	pdf-lib
Read/View PDF	pdf.js
PDF to Images	pdf.js + Canvas
Images to PDF	jsPDF
PDF to PowerPoint	pdf.js + PptxGenJS
Remove Password	@pdfsmaller/pdf-decrypt
Protect/Encrypt	pdf-lib
Compress PDF	pdf-lib + image re-encoding
Number Pages	pdf-lib

4. Text, Audio & Calculator Tools (19 Tools)

This category is broad and includes text processing, encryption, audio, and math calculator tools. All rely on native JavaScript and standard browser APIs.

How it works by type

Type	Technology
Text converter, compare, counter	Pure JavaScript (String methods + LCS)
MD5/SHA hashing	Web Crypto API (SHA) + local MD5 function
Base64, URL Decoder	atob/btoa, decodeURIComponent
Password generator	crypto.getRandomValues
JSON Formatter	JSON.parse + JSON.stringify
Text to Speech	Web Speech API (SpeechSynthesis)
Age, Percentage, VAT calculators	Pure JavaScript (Date + Math)
BMI/BMR calculator	Mifflin-St Jeor equation (JS)
Currency converter	External API (live exchange rate)

Tools in this category

text-converter.php url-decoder.php whatsapp-link-generator.php ats-cv.php hash-generator.php base64.php word-counter.php text-to-speech.php json-formatter.php text-compare.php lorem-ipsum.php password-gen.php age-calculator.php birth-day.php age-calc.php percentage-calculator.php vat-calculator.php bmr-bmi-calculator.php currency-converter.php

5. Image & Video Tools (17 Tools)

These tools rely on the Canvas API for image processing, and Web Audio API / MediaRecorder for video and audio processing.

How it works by type

Type	Technology
Compress, Resize, Convert formats	Canvas API + toBlob
Crop Images	Cropper.js
Remove Background	MediaPipe Selfie Segmentation (local AI)
Color Extractor	Read Canvas pixels
Watermark	Draw text/image on Canvas
Favicon Generator	Canvas + convert to DataURL
SVG to PNG	Load SVG as image + Canvas
Video to GIF	MediaRecorder + gif.js
Video to MP3	Web Audio API + MediaRecorder
Trim Video	MediaRecorder + Canvas
Convert Video	FFmpeg.wasm
WAV to MP3	lamejs
ZIP Extractor	JSZip
QR Generator	qrcode.js

Tools in this category

color-extractor.php convert-images.php convert-to-webp.php heic-to-jpg.php image-to-webp.php compress-images.php add-watermark.php remove-background.php crop-images.php resize-image.php favicon-generator.php svg-to-png.php

video-to-gif.php video-to-mp3.php trim-video.php convert-video.php wav-to-mp3.php

qr-generator.php zip-extractor.php what-is-my-ip.php internet-speed-test.php

6. Cloud Tools (Only 3)

For full transparency, we note that only 3 tools use external cloud services because they require specialized server-side libraries that do not run efficiently in the browser. These tools are clearly marked with a yellow warning banner on their pages:

Tool	Cloud Service	Why?
pdf-to-excel.php	ConvertAPI	Converting PDF tables to Excel requires advanced table OCR
url-to-pdf.php	Microlink	Rendering full web pages (including JS) to PDF
url-shortener.php	Lejumo	URL shortening requires a central database

7. Tech Stack

We use a set of the best open-source libraries, all running in the browser:

Library	Usage	License
pdf.js	Read and render PDF	Apache 2.0
pdf-lib	Create and modify PDF	MIT
jsPDF	Create PDF from images	MIT
Tesseract.js	OCR	Apache 2.0
Cropper.js	Crop images	MIT
MediaPipe	Remove background (AI)	Apache 2.0
PptxGenJS	Create PowerPoint	MIT
JSZip	ZIP	MIT / GPLv3
FFmpeg.wasm	Video conversion	LGPL
qrcode.js	QR generator	MIT
html2canvas	Convert HTML to image	MIT
Tailwind CSS	Design (CDN)	MIT

8. Limitations

Because the tools run in the browser, there are some natural limitations you should know about:

• Memory: Very large files (over 100 MB) may consume a lot of memory and slow down the browser. We recommend files under 50 MB.
• Speed: Local processing depends on your device. Older devices may be slower.
• Browser compatibility: Tools work best on modern Chrome, Edge, Firefox, and Safari. Some older browsers may not support WebAssembly or certain APIs.
• Cloud tools: Only 3 tools require an internet connection (because they use external services).
• Complex conversions: For example, converting PDF to Word with perfect formatting may not reach 100% accuracy because the original formatting may be complex (tables, custom fonts, etc.).