Free online tools for developers, writers and everyday life: the complete guide
AdvertisementMost of us open a free online tool a few times a week: to format some JSON, shrink a photo, work out a loan payment or count the words in an essay. The experience is often poor: pages covered in pop-ups, forced sign-ups, files uploaded to a server you know nothing about, results hidden behind a paywall. This site's tools were built for the opposite experience. Each one does a single job, runs in your browser, needs no account and sends nothing to a server. This is the complete guide: what is available, who each tool is for and where to read more about the ones you use.
How the tools work
All tools share the same principles:
- They run on your device. The calculation, formatting or conversion happens in your browser using JavaScript. What you type or choose, whether text, a photo or a salary, is not uploaded, so confidential material stays with you. Once a page has loaded, many tools work without a connection.
- No sign-up and no limits. There is nothing to log in to, no daily quota and no watermark.
- Honest explanations. Every tool page includes a short guide, a worked example and answers to common questions, and the longer guides linked below explain the ideas in depth.
- Estimates are labelled. Finance and health tools tell you what they do not cover, and they are not substitutes for professional advice.
You can browse them all on the tools page. Here they are grouped by purpose.
For developers and technical work
| Tool | What it does | Guide |
|---|---|---|
| JSON Formatter | Format, validate and minify JSON, and pinpoint syntax errors | Read |
| Regex Tester | Try regular expressions against text with live highlighting and groups | Read |
| URL Encoder & Decoder | Percent-encode or decode text for use in links | Read |
| Unix Timestamp Converter | Convert timestamps to dates and back | Read |
| UUID Generator | Create unique identifiers | Read |
| HTML Viewer | Preview HTML safely in an isolated frame | Read |
| Hash & Encode Toolkit | Hashes and Base64 and other encodings | Read |
Typical day: you receive an API response, paste it into the JSON Formatter to read it, convert a created_at value with the timestamp tool, build the request link with the URL encoder, and use the regex tester to pull a value out of a log line. Each takes seconds.
For writers, students and editors
| Tool | What it does | Guide |
|---|---|---|
| Word Counter | Words, characters, sentences and reading time | Read |
| Case Converter | Upper, lower, title, sentence, camel, snake and more | Read |
| Text Diff Checker | See what changed between two versions | Read |
| Markdown Viewer | Write Markdown and see the formatted result | Read |
| Invisible Character Cleaner | Find and remove hidden characters in pasted text | Read |
| Placeholder text generator | Placeholder text for layouts | Read |
A writer's workflow could be: draft in Markdown, check the word count against the limit, compare the editor's version with the original, clean the pasted text of strange spaces, and fix the capitalisation of headings.
For design and images
| Tool | What it does | Guide |
|---|---|---|
| Image Compressor | Shrink JPG, PNG and WebP images privately | Read |
| Image Color Picker | Pick exact colour values from a photo | Read |
| QR Code Generator | Make a static QR code and download it as PNG | Read |
For money and business
| Tool | What it does | Guide |
|---|---|---|
| EMI Calculator | Monthly loan instalment, total interest and schedule | Read |
| GST Calculator | Add or remove GST, with the CGST, SGST or IGST split | Read |
| SIP Calculator | Estimate growth of a monthly investment | Read |
| Compound Interest Calculator | Lump-sum growth and effective rate | Read |
| FD & RD Calculator | Fixed and recurring deposit maturity | Read |
| Income Tax Calculator (India) | Compare the new and old regimes | Read |
| Discount & Profit Margin Calculator | Discounts, margin, markup and target prices | Read |
These work well together: use the GST Calculator to remove tax from an invoice, the margin calculator to check your profit, the EMI Calculator to finance equipment, and the income tax calculator to see what you will owe at the end of the year.
For everyday life
| Tool | What it does | Guide |
|---|---|---|
| Unit Converter | Length, weight, volume and temperature | Read |
| Percentage Calculator | The four everyday percentage questions | Read |
| Age & Date Difference Calculator | Exact age and days between dates | Read |
| Number to Words Converter | Amounts in words, in lakh or million | Read |
| BMI Calculator | Body mass index with WHO and Asian Indian categories | Read |
| Password Generator | Strong random passwords | Read |
Which tool for which problem?
| If you want to… | Use |
|---|---|
| Read a messy API response | JSON Formatter |
| Make a web page address safe | URL Encoder |
| Check when a log entry happened | Timestamp Converter |
| Count the words in an essay | Word Counter |
| See what an editor changed | Text Diff Checker |
| Make a photo load faster | Image Compressor |
| Print a scannable link | QR Code Generator |
| Know what a loan will cost | EMI Calculator |
| Take GST out of a bill | GST Calculator |
| Write a cheque amount | Number to Words |
| Make a login secure | Password Generator |
Why browser-based tools are safer
When a tool uploads your file or text to a server, you must trust that service with it. Photos can carry location data, text can hold personal details, a salary figure is private. A browser-based tool never has to be trusted with your data, because the data never leaves your device. You can check this yourself: open the browser's network panel while using a tool and see that no request carries your input. The trade-off is that the tool depends on your own device's power, but for nearly all everyday tasks that is more than enough.
Using the tools well
- Treat calculators as estimates. They do the arithmetic correctly, but your bank, your tax adviser or your doctor has the final say.
- Check the units and the year. Many errors come from the wrong unit (seconds against milliseconds, US against UK gallons) or old rules (tax rates change each year).
- Keep originals. Compression, cleaning and conversion change the result; keep the source file.
- Use the guides. If a result surprises you, the guide for the tool usually explains why.
Learning more
The tools are one part of the site. If you want to understand how they are built or how to build something similar, the free courses start from the beginning: HTML, CSS, MySQL, PHP, jQuery and WordPress. Each lesson has runnable examples and a quiz, and each course ends with an exam and a certificate.
Quick answers
Do I need an account? No. Open a tool and use it.
Are my files uploaded? No. The tools run in your browser.
Are the tools really free? Yes. The site is supported by advertising, not by fees.
Which are the most useful? It depends on your work: developers tend to use the JSON Formatter and the Regex Tester, writers the Word Counter, and everyone the Unit Converter and the Percentage Calculator.
How do I suggest a new tool? Use the contact page to tell us what you need.