Browser calculators and generators.
Use practical design, network, date, sizing, and utility calculators with no remote processing.
Work locally, download directly
Quick reference tools for calculations and generated values where inputs can remain in the current browser tab.
QR Code Studio
Generate custom QR codes or decode them from an image.
CSV & JSON Converter
Convert quoted CSV, TSV, and JSON data without uploading it.
CSS Gradient Generator
Design a positioned two-color linear gradient and copy its CSS declaration.
CSS Box Shadow Generator
Preview offsets, blur, spread, color, and inset CSS box shadows.
CSS Border Radius Generator
Preview and generate independent CSS radius values for all four corners.
CSS Clamp Calculator
Calculate fluid responsive CSS sizing between viewport and value limits.
Color Contrast Checker
Measure color contrast against WCAG AA, AAA, large-text, and UI thresholds.
PX & REM Converter
Convert CSS pixel and root-relative REM lengths using a configurable root size.
Aspect Ratio Calculator
Reduce image or video proportions and calculate a matching target dimension.
Cubic Bezier Generator
Create and interactively preview custom CSS transition timing functions.
Date Difference Calculator
Calculate elapsed or inclusive days, weeks, and hours between calendar dates.
Business Days Calculator
Count Monday-to-Friday workdays while excluding custom weekday holidays.
Time Zone Converter
Convert an explicit ISO instant into a daylight-saving-aware IANA time zone.
Duration Converter
Convert milliseconds, seconds, minutes, hours, and days with ISO 8601 output.
IPv4 Subnet Calculator
Calculate CIDR boundaries, masks, broadcast address, and usable host range.
IPv4 Address Converter
Convert dotted IPv4 addresses into integer, hexadecimal, and binary forms.
IPv4 Range to CIDR
Summarize an inclusive IPv4 address range with the smallest exact CIDR set.
MAC Address Formatter
Validate, normalize, and classify common 48-bit MAC address notation.
Data Size Converter
Convert bytes and decimal or binary storage units without mixing MB and MiB.
Download Time Calculator
Estimate file transfer time from size, connection speed, and protocol overhead.
Video Bitrate Calculator
Calculate an average video bitrate for a target size, duration, and audio stream.
Image Print Size Calculator
Convert image pixel dimensions and DPI into physical inches and centimeters.
File Difference Checker
Compare two text or code files with a clear line-level diff.
Base64 Encoder & Decoder
Encode files as Base64 or restore pasted Base64 data locally.
JSON Formatter & Validator
Validate, format, minify, and sort JSON without sending data away.
XML Formatter & Validator
Validate, format, and minify XML without uploading its contents.
Text Case Converter
Convert text into readable, URL, or programming-friendly casing.
Line Sorter & Cleaner
Trim, sort, deduplicate, and remove blank lines locally.
Batch Find & Replace
Replace text or regular expressions across multiple local files.
URL Encoder & Decoder
Encode or decode URL components, form values, and full URL paths.
HTML Entity Encoder & Decoder
Safely encode markup characters or decode HTML entities locally.
UUID Generator
Create secure UUID v4 identifiers in configurable local batches.
Regex Tester & Replacer
Test regular expressions, inspect captures, and preview replacements.
Text Counter & Analyzer
Count words, characters, structure, reading time, and frequent terms.
Unix Timestamp Converter
Convert Unix timestamps and local dates in both directions.