Technology · Tools · Innovation
Free online tools
Powerful tools. Simple solutions.
Discover fast, free online utilities for everyday tasks, development, documents, images and engineering.
Popular tools
Explore all- Compress PDFReduce PDF file sizes
- Image ResizerResize images instantly
- QR Code GeneratorCreate QR codes
- JSON Formatter & ValidatorFormat and validate JSON
- Merge PDFCombine PDF files into one document
- Password GeneratorGenerate a password on your device
- Unit ConverterConvert length, mass, area, volume, speed, pressure and temperature
- Steel Weight CalculatorEstimate the weight of bars, plate, pipe and angle
Browse by category
- 01
PDF & Document
Merge, split, compress and turn images into PDFs. The file never leaves your browser.
- 02
Image & Design
Resize, compress, convert and sample colour from JPG, PNG and WebP images.
- 03
Developer
Format JSON, encode text and test regular expressions without sending your data away.
- 04
Generators & Utilities
Create QR codes, passwords, UUIDs and random numbers when you need them.
- 05
Calculators & Converters
Convert units, percentages, dates and file sizes with the working shown.
- 06
Engineering
Estimate steel weight, rebar, concrete and geometry for planning. Confirm the result against the drawings.
All tools
Search or filter the full set. Each tool has its own page.
- PDF Tools
Merge PDF
Combine PDF files into one document
- PDF Tools
Split PDF
Extract pages or save every page separately
- PDF Tools
Compress PDF
Reduce PDF file sizes
- PDF Tools
Image to PDF
Place JPG, PNG and WebP images on PDF pages
- Image Tools
Image Resizer
Resize images instantly
- Image Tools
Image Compressor
Reduce image file size before you send it
- Image Tools
Image Format Converter
Convert between JPG, PNG and WebP
- Image ToolsNew
Color Palette Generator
Build a palette or sample one from a photo
- Developer Tools
JSON Formatter & Validator
Format and validate JSON
- Developer Tools
Base64 Encoder / Decoder
Encode and decode text or files
- Developer Tools
URL Encoder / Decoder
Encode and decode URL components
- Developer ToolsNew
Regex Tester
Test a JavaScript regular expression
- Generators
QR Code Generator
Create QR codes
- Generators
Password Generator
Generate a password on your device
- Generators
UUID Generator
Create version 4 UUIDs
- Generators
Random Number Generator
Draw integers or decimals in a range
- Calculators
Unit Converter
Convert length, mass, area, volume, speed, pressure and temperature
- Calculators
Percentage Calculator
Find a percentage, a change, or a share
- Calculators
Date Difference Calculator
Count days, weekdays and months between two dates
- Calculators
File Size Converter
Convert bytes, kilobytes, megabytes and beyond
- EngineeringNew
Steel Weight Calculator
Estimate the weight of bars, plate, pipe and angle
- EngineeringNew
Rebar Quantity Estimator
Estimate bar count and weight for a simple member
- Engineering
Concrete Volume Calculator
Find volume and a simple material estimate
- Engineering
Area & Volume Calculator
Areas and volumes of common shapes
New and featured
Featured
Color Palette Generator
Generate harmonious colours from a base hex value, or extract the dominant colours from an image. Copy any swatch as you go.
Featured
Regex Tester
Try a JavaScript regular expression against sample text, inspect capture groups, and preview a replacement. The pattern is compiled with the RegExp engine in your browser.
Featured
Steel Weight Calculator
Calculate steel weight from section size, length and quantity. Round bar uses the circular area and a density of 7850 kg/m³, the basis of standard reinforcement weight tables.
Featured
Rebar Quantity Estimator
Estimate reinforcement quantity for a slab, a beam or a column, or from a known number of bars. Weights use 7850 kg/m³. This is a planning figure, not a bar bending schedule.
Why RS Labs
Free
Every tool is free to use. There is no account and no payment step in front of the work.
Simple
Open a tool, finish the task, and leave. The page is the product.
Private
Files and text are processed in your browser. They are not uploaded to RS Labs.
Accessible
Labels, keyboard access and a layout that stays readable on a small screen.