Tools that stay in your browser

Format, encode, generate — privately. No servers process your data.

Free browser tools that never leave your device.

Favorite tools

No favorited tools yet. Tap the ☆ on a tool card to save it here.

Popular

Beautify, minify and validate JSON in your browser.

Base64 Encode / Decode

Encode or decode Base64 text locally.

URL Encode / Decode

Percent-encode or decode URL components.

MD5, SHA-1, SHA-256 and more — computed locally.

Generate UUID v4 identifiers in bulk.

Password Generator

Create strong random passwords offline.

Convert between Unix time and human-readable dates.

Query String Parser

Parse URL query strings to JSON and back.

Convert CSV tables to JSON objects and back.

Color Converter

Convert between HEX and RGB color formats.

Count words, characters and reading time.

Lorem Ipsum Generator

Generate placeholder text for mockups.

Turn titles into URL-friendly slugs.

QR Code Generator

Create QR codes from text or URLs locally.

Image to Base64

Convert an image file to a Base64 data URL.

Image Format Convert

Convert images between PNG, JPEG and WebP in the browser.

Compound Interest & DCA

Estimate future value with compounding and monthly contributions — locally.

Loan Payment Calculator

Equal-payment or equal-principal loan schedules. Runs in your browser.

Compute NPV and IRR from a list of cashflows. No data leaves your device.

Price change and net P/L after buy/sell fees.

FX Converter (manual rate)

Convert amounts with a rate you enter. No live market quotes.

Interest Rate Converter

Convert between daily, monthly and annual rates (nominal / effective).

Installment Fee → APR

Turn advertised monthly installment fees into an approximate APR.

All tools

Developer

Encode, format and generate for daily coding

Beautify, minify and validate JSON in your browser.

Base64 Encode / Decode

Encode or decode Base64 text locally.

URL Encode / Decode

Percent-encode or decode URL components.

MD5, SHA-1, SHA-256 and more — computed locally.

Generate UUID v4 identifiers in bulk.

Password Generator

Create strong random passwords offline.

Generate random hex or alphanumeric strings.

Convert between Unix time and human-readable dates.

Decode JWT header and payload without sending tokens away.

Test regular expressions with live matches.

Encode or decode HTML special characters.

Query String Parser

Parse URL query strings to JSON and back.

Convert CSV tables to JSON objects and back.

Beautify or minify XML in your browser.

Break down a 5-field cron expression.

Color Converter

Convert between HEX and RGB color formats.

Number Base Converter

Convert numbers between binary, octal, decimal and hex.

Text

Count, convert and generate plain text

Count words, characters and reading time.

UPPER, lower, Title Case, camelCase and more.

Lorem Ipsum Generator

Generate placeholder text for mockups.

Find and Replace

Find and replace text, with optional regex.

Compare two texts line by line.

Turn titles into URL-friendly slugs.

Files & visual

Images, QR and color helpers

QR Code Generator

Create QR codes from text or URLs locally.

Image to Base64

Convert an image file to a Base64 data URL.

Image Format Convert

Convert images between PNG, JPEG and WebP in the browser.

Contrast Checker

Check WCAG contrast ratio between two colors.

Finance

Local calculators for loans, returns and money math

Compound Interest & DCA

Estimate future value with compounding and monthly contributions — locally.

Loan Payment Calculator

Equal-payment or equal-principal loan schedules. Runs in your browser.

Compute NPV and IRR from a list of cashflows. No data leaves your device.

Price change and net P/L after buy/sell fees.

FX Converter (manual rate)

Convert amounts with a rate you enter. No live market quotes.

Split tax-inclusive prices or add VAT to a net amount.

Interest Rate Converter

Convert between daily, monthly and annual rates (nominal / effective).

Inflation Purchasing Power

See how inflation changes purchasing power over years.

Installment Fee → APR

Turn advertised monthly installment fees into an approximate APR.

Money Formatter

Format numbers with locale currency styles and decimal places.

How LocalKit works

LocalKit is a free, local-first toolbox. Every tool runs in your browser—text and files never leave your device. No account required. Works in Chrome, Safari, Edge and Firefox.

Choose LocalKit when you want free utilities without accounts or uploading text and files to a converter SaaS. Scripts load from this site only; there is no third-party analytics pixel on tool pages. Prefer LocalKit over random online paste sites when the payload is sensitive (tokens, IDs, private JSON).