A tool for the job, with the method written down.
Merge a PDF, shrink a photo, check an EMI, or format JSON. Finance and health calculators include the formula and a worked example, and each tool page states its limits.
Utilities we build, with the limits written on the page.
ToolSink is an independent toolkit from India: we build the utilities and write the guides ourselves. The point is a finished job — merge a PDF, shrink a photo, format JSON, draft a resume — without an account or a file upload you did not ask for.
Start with Text to Speech, Speech to Text, PDF Studio or Image Studio. Longer how-tos live on the blog.
- Free to use · No sign-up requiredNo account, no email, no watermark on your files.
- Privacy-firstMany tools process your files locally in your browser. Tools that require server-side processing may handle data differently.
- Zero clutterNo pop-ups, no interstitials, no dark patterns. Just tools that work.
Who we are and how we write: About · Editorial standards · All tools
Browse by category
Find tools grouped the way you think.
Merge, split, compress and edit PDF files effortlessly.
Convert, compress and resize images without quality loss.
Count, transform and compare text instantly.
JSON, Base64, UUID and other utilities for developers.
EMI, SIP, GST and other finance calculators.
BMI and health-related calculators for daily use.
Handy calculators and helpers for students.
Bios, captions, hashtags, WhatsApp message formatting and a visual post designer for Instagram, LinkedIn and WhatsApp.
QR & barcodes, passwords, speech tools, invoice & resume builders, colour picker and everyday calculators.
Trim, compress and convert videos locally.
Trim, edit and convert audio files locally.
Popular tools
Word Counter
Count words, sentences and paragraphs instantly.
JPG to PNG
Convert JPG images to PNG.
SVG to PNG
Convert SVG vectors to PNG format.
Image Compressor
Reduce image size without losing quality.
Image Background Remover
Remove image background 100% free in your browser.
OG Image Generator
Design free Open Graph 1200x630 social media sharing images for your website.
Merge PDF
Combine multiple PDFs into one.
Image to PDF
Convert JPG or PNG images into a single PDF.
JSON Formatter
Format, validate and minify JSON.
EMI Calculator
Calculate monthly loan EMI.
Currency Converter
Convert currencies with live exchange rates.
Video Studio
All-in-one video editor: trim, compress, convert, remove audio, speed, watermark, and to-gif.
Practical guides from the ToolSink blog
Step-by-step articles on PDFs, images, encoding, passwords and more — written to help you use our free tools with confidence.
Which ToolSink jobs stay in the browser, and which ones upload
A first-party note on how ToolSink actually processes files: calculators, Create PDF, and rotate stay in the browser, while merge, split, compress, and images-to-PDF go to our API for that request only.
Read articleRandom Password Generators: The Actual Math Behind "Uncrackable"
How password entropy is actually calculated, why the randomness source matters as much as the password itself, and a memorable alternative for master passwords.
Read articleSQL Formatting Best Practices for Clean Code
Practical SQL formatting rules — capitalization, CTEs over nested subqueries, explicit JOINs, and why GROUP BY column indexes are a silent bug waiting to happen.
Read articleConverting SVG to PNG: What Actually Happens During Rasterization
Why SVGs need an explicit size before converting to PNG, the viewBox gotcha that trips up conversions, and a code example for batch converting programmatically.
Read articleText Case Conversion: Styles, When to Use Each, and How to Convert Programmatically
The standard text case styles, where each one is actually expected, the real reason hyphens beat underscores in URLs, and working code for converting between cases.
Read articleURL Encoding Explained: The Rules and the Bug Everyone Hits Eventually
How percent-encoding actually works, the full reference table, and the encodeURI vs encodeURIComponent mistake that breaks query strings in production.
Read articleKept current
We publish a short log when a guide is rewritten, a duplicate page is retired, or a tool is taken off the public directory. Latest entry: 4 October 2026 — EMI, SIP, FD, and BMI pages now include a formula and a worked example, and near-duplicate widgets were removed from the directory.