Free Online Web Tools & Calculators
A single toolkit for the small jobs that interrupt real work - converting a file, hashing a string, generating test data, sorting a list or running a calculation. Most tools run entirely in your browser, so whatever you paste in stays on your own device.
- 119+ Tools & calculators
- 12 Categories
- $0 Cost, always
Text & SEO Tools
Write, analyse and clean up copy - count words, measure keyword density and turn text into markup.
Text Case Converter
Switch text between upper, lower, sentence, title and inverse case.
Character & Word Counter
Count words, characters, sentences, paragraphs, spaces and pages.
Keyword Density Checker
Measure keyword frequency and density for on-page SEO.
Word / Text to HTML Converter
Convert text or Word content into clean HTML with a visual editor.
HTML Escape / Unescape
Escape, unescape, strip tags and tidy raw HTML in one pass.
Email & URL Extractor
Pull every e-mail address or URL out of any block of text.
Word Frequency Counter
See which words repeat most often across your content.
Image Tools
Edit, crop, encode and decode images entirely in your browser - no file ever leaves your device.
Image to Base64 Converter
Turn any image into a Base64 string ready for HTML or CSS.
Base64 to Image Decoder
Decode a Base64 string back into an image and download it.
Online Photo Editor
Retouch, filter and adjust photos in a full-featured editor.
Online Image Cropper
Crop, flip, rotate and zoom an image, then download the result.
Image Metadata Viewer
Read EXIF, GPS, XMP, IPTC and hashes without uploading a file.
Signature Drawing Board
Draw a digital signature with a mouse, finger or stylus.
Picture Quotes Maker
Lay a quote over a picture and share it on social media.
HTML Tools
Generate, minify and tidy markup - tables, lists, mailto links and pop-ups without hand-writing HTML.
HTML Minifier
Compress HTML by stripping comments, spaces and line breaks.
HTML Beautifier
Make minified HTML readable again with proper indentation.
Mailto Link Generator
Build an HTML mailto link with subject, body, cc and bcc.
Pop-up Window Generator
Create the JavaScript pop-up window code for your page.
HTML List Generator
Turn plain text into ordered or unordered HTML lists.
HTML Table Generator
Build an HTML table on the fly and copy the generated markup.
URLs to HTML Hyperlinks
Convert plain URLs into ready-to-use HTML anchor tags.
Alphabetize List
Sort any list alphabetically with case and reverse options.
Remove Line Breaks
Strip stray line and paragraph breaks out of pasted text.
Remove Duplicate Lines
Delete repeated lines and keep every entry in a list unique.
CSV to HTML Table
Upload a CSV file and preview it as a tabular HTML table.
HTML Escape / Strip Tags
Escape or unescape HTML entities and remove tags safely.
Data Generators
Realistic test data for developers and QA - mock records, dummy copy, e-mails, passwords and card numbers.
Custom Mock Data Generator
Build test data and export to CSV, JSON, XML, SQL or arrays.
Lorem Ipsum Generator
Generate placeholder words, sentences, paragraphs or HTML.
Real Content Generator
Produce readable dummy copy in English, German or French.
E-mail Address Generator
Create lists of random, safe or company-domain addresses.
Credit Card Generator
Generate test card numbers, CVV and expiry for sandboxes.
Passphrase Generator
Build long, memorable passphrases that resist cracking.
Strong Password Generator
Generate secure passwords to your own complexity policy.
Random Number Generator
Draw cryptographically secure random integers in a range.
Encoders & Decoders
Encode, decode and hash strings - Base64, URL encoding, Morse code and eleven hashing algorithms.
Base64 Encode
Encode any text or data into a Base64 string.
Base64 Decode
Decode a Base64 string back into readable text.
URL Encoder & Decoder
Percent-encode or decode text for safe use inside a URL.
Morse Code Translator
Translate text to Morse code and Morse code back to text.
Password Hash Generator
Hash a string with MD5, SHA, CRC32, Whirlpool and more.
MD5 Hash Generator
Produce the 128-bit MD5 digest of any string.
SHA1 Hash Generator
Produce the 40-character SHA-1 hexadecimal digest.
SHA256 Hash Generator
Produce a fixed-size 256-bit SHA-2 hash of any input.
SHA512 Hash Generator
Produce a 128-digit hexadecimal SHA-512 digest.
CRC32 Checksum Generator
Produce a CRC32 checksum for integrity checks, not security.
Whirlpool Hash Generator
Produce a 512-bit Whirlpool hash result.
RIPEMD160 Hash Generator
Produce a 160-bit RIPEMD cryptographic hash.
Bcrypt Hash Generator
Hash a password with bcrypt and a per-hash salt.
Network Tools
Look up what the internet knows about an address - your own IP, a domain's DNS records and subnet maths.
My IP & User Agent
See your public IP, approximate location and browser details.
DNS Lookup Tool
Check A, MX, NS, TXT and other DNS records for a domain.
IPv4 Network Calculator
Work out subnet mask, host range, broadcast and network ID.
IPv6 Network Calculator
Expand IPv6 notation and read off the full address range.
Converters
Translate data between formats - text to binary, hex, octal or ASCII, plus QR codes and barcodes.
QR Code Generator
Create and download QR codes for URLs, text, SMS or vCards.
Barcode Generator
Generate CODE128, EAN, CODE39, ITF, MSI and Codabar codes.
Text to Binary Converter
Translate text into binary and binary back into text.
Text to Hexadecimal Converter
Convert text to hex and hexadecimal back to plain text.
Text to ASCII Converter
Convert Unicode text into ASCII codes and back again.
Text to Octal Converter
Convert UTF-8 text into octal numbers and back to text.
Decimal Number Converter
Convert decimal into binary, octal and hexadecimal.
Binary Number Converter
Convert binary into decimal, octal and hexadecimal.
Octal Number Converter
Convert octal into binary, decimal and hexadecimal.
Hexadecimal Number Converter
Convert hex into binary, decimal and octal values.
Serialize & Unserialize
Move between serialized data, JSON, XML and query strings.
Date & Time Tools
Add, subtract and compare dates, translate Unix timestamps and read the time in any locale.
Date Calculator (Add / Subtract)
Add or subtract years, months, weeks or days from a date.
Age & Date Difference Calculator
Measure the gap between two dates down to milliseconds.
Localized Date & Time Formats
View the current date and time in dozens of locale formats.
Unix Timestamp Converter
Turn epoch seconds or milliseconds into a readable date.
Unit Converters
Convert between metric and imperial units of length, time and temperature.
Length Unit Converter
Metric, imperial, Chinese and astronomical distance units.
Time Unit Converter
Convert between picoseconds, seconds, days, years and more.
Temperature Converter
Celsius, Fahrenheit, Kelvin, Rankine and Reaumur.
Basic Math Calculators
Everyday arithmetic - sums, products, roots, percentages and profit, with the working shown.
Addition Calculator
Add two numbers and read off the sum instantly.
Subtraction Calculator
Subtract one number from another and see the difference.
Multiplication Calculator
Multiply two numbers and read off the product.
Division Calculator
Divide numbers and get the quotient and remainder.
Square Calculator
Square any number, or work back from a square.
Square Root Calculator
Find the square root of any number you enter.
Percentage Calculator
Work out percentages, increases and decreases.
Online Code Editors
Syntax-highlighted editors that run in the browser - try a snippet without installing anything.
JavaScript Editor
Write and edit JavaScript with syntax highlighting.
HTML Editor
Edit HTML and preview the rendered result as you type.
PHP Editor
Edit PHP snippets in a highlighted browser editor.
CSS Editor
Write CSS with highlighting and an instant preview.
Python Editor
Write Python in the browser with syntax highlighting.
JSON Editor
Edit, format and check JSON documents for errors.
Java Editor
Edit Java source with syntax highlighting.
Ruby Editor
Write Ruby in a lightweight browser editor.
SQL Editor
Write and format SQL queries with highlighting.
C / C++ Editor
Edit C and C++ source directly in the browser.
Golang Editor
Write Go code with syntax highlighting.
C# Editor
Edit C# source in a highlighted browser editor.
Health & Body Calculators
Body composition and fitness estimates built on published clinical formulas, with the source cited on every page.
Body Mass Index (BMI) Calculator
Calculate BMI instantly in metric or imperial units.
BMR Calculator
Estimate resting energy needs and daily calorie targets.
Ideal Body Weight Calculator
Compare ideal weight across several clinical formulas.
Body Fat Percentage Calculator
Estimate body fat from BMI or circumference measurements.
Waist-to-Hip Ratio Calculator
Assess fat distribution and cardiometabolic risk pattern.
Waist-to-Height Ratio Calculator
Compare waist to height for a simple central-obesity screen.
Daily Calorie Needs Calculator
Estimate maintenance calories (TDEE) and a macro split.
Heart Rate Zone Calculator
Estimate training zones from several max heart rate formulas.
Calories Burned by Distance
Estimate burn from distance, pace, activity and body weight.
Body Frame Size Calculator
Find your frame category from elbow or wrist measurements.
Lean Body Mass Calculator
Estimate lean mass using validated clinical formulas.
Body Adiposity Index Calculator
Estimate body fat from hip circumference and height.
Everyday Financial Calculators
Work out tax, tips and take-home pay before you commit to a number.
Sales Tax Calculator
Work out the pre-tax price, the tax amount and the total.
Tip Calculator
Split a bill and work out the tip owed per person.
Profit Calculator
Calculate profit and margin from cost and selling price.
Hourly to Salary Calculator
Turn an hourly rate into weekly, monthly and yearly pay.
Salary Increase Calculator
Project a raise across future pay periods.
Investment & Savings Calculators
Project what a deposit, a rate or a lump sum is worth at maturity.
Simple & Compound Interest Calculator
Calculate maturity value under either interest method.
Fixed Deposit (TDR) Calculator
Work out the periodic interest payout and maturity value.
Fixed Deposit (STDR) Calculator
Work out cumulative compounding maturity value.
Recurring Deposit (DPS) Calculator
Project monthly savings growth and the maturity amount.
Return on Investment (ROI) Calculator
Calculate total gain or loss and annualised ROI.
Rule of 72 Calculator
Estimate doubling time, or the return rate needed for it.
Loan & Mortgage Calculators
See the instalment, the interest and the real cost before you sign for borrowing.
Loan Calculator
Calculate the EMI and a full amortisation schedule.
Auto Loan Calculator
Price vehicle finance with tax, trade-in and fees included.
Mortgage Calculator
Estimate the payment, total cost and payoff timeline.
Credit Card Payoff Calculator
See payoff time and interest cost for a fixed payment.
Minimum Payment Calculator
See what paying only the minimum really ends up costing.
Personal Loan Calculator
Estimate EMI, APR, fees and the full payoff timeline.
General APR Calculator
Compare a nominal rate against the true APR you pay.
Mortgage APR Calculator
Find the real APR and total repayment cost of a mortgage.
Why use OnlineWebToolkit
Every page here is a single-purpose utility that loads fast, does one job and gets out of the way.
Private by default
Most tools run entirely in your browser, so the text, images and numbers you paste in never leave your device.
No account, no install
Every page is public and free to use. There is nothing to sign up for, download or configure before you start.
Works on any device
The whole toolkit is responsive, so a phone or tablet gets the same tools as a desktop browser.
Documented and sourced
Each tool has a written guide, and the health and financial calculators cite the published formula they implement.
Frequently Asked Questions
What the tools do with your data, what they cost and how to find the one you need.
Are the tools on OnlineWebToolkit free to use?
Yes. Every tool and calculator on the site is free and public, with no account, trial or usage limit. The site is funded by advertising, which is why you will see ad slots alongside the tools.
Is the data I paste into a tool uploaded to your server?
For the large majority of the tools, no. They are written in JavaScript and run inside your own browser, so the text, image or numbers you enter are never transmitted anywhere. A small number of tools genuinely need a server to work - a DNS lookup has to query a name server, for example - and those are the only ones that send your input to us.
Do I need to install anything or create an account?
No. There is nothing to download and nothing to sign up for. Open the page for the tool you need and it is ready to use immediately in any modern browser on desktop, tablet or phone.
Can I use these tools on a phone or tablet?
Yes. The whole site is responsive, so every tool and calculator reflows to fit a small screen. The drawing, cropping and photo editing tools also accept touch input.
How accurate are the health and financial calculators?
Each one implements a specific published formula, and the page names the paper or standard it comes from so you can check the method yourself. They are estimates for general information only and are not a substitute for advice from a doctor or a qualified financial adviser.
How do I find a specific tool quickly?
Use the search box at the top of this page, or in the site header on any other page, to search all of the tools by name. You can also browse by category using the twelve category links below the search box.