Everyday Dev Tools

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Local-first browser utilities

Everyday developer tools,
without the clutter.

Format data, inspect values and make quick conversions. Each tool runs in your browser, with no account and no upload step.

Browse 13 tools How your data stays private

Tool directory

Find the right utility

13 tools

JSON & data

3 tools
JSON & data

JSON Formatter

Format, validate or minify JSON in your browser, with readable syntax errors and configurable indentation.

JSON & data

JSON Diff

Compare two JSON documents by structure and see added, removed and changed values at exact paths.

JSON & data

JSON ↔ CSV

Convert arrays of JSON records to RFC-style CSV, or turn a header-based CSV file into JSON objects.

Time & automation

2 tools
Time & automation

Unix Timestamp

Convert Unix seconds, milliseconds, microseconds or nanoseconds to UTC, and convert ISO dates back to exact epoch units.

Time & automation

Cron Expression

Build and validate five-field cron expressions, explain each field and calculate upcoming runs in local time or UTC.

Encoding & security

3 tools
Encoding & security

JWT Decoder

Decode a three-part JWT header and payload, inspect time claims and keep the token entirely in your browser.

Encoding & security

Base64 Encoder

Encode UTF-8 text as standard Base64 or unpadded Base64URL, and decode either alphabet back to text.

Encoding & security

SHA Hash Generator

Calculate SHA-256, SHA-384 or SHA-512 for UTF-8 text or a local file with the browser Web Crypto API.

Identifiers & web

2 tools
Identifiers & web

UUID Generator

Generate cryptographic UUID v4 or time-ordered UUID v7 values in bulk and inspect version, variant and v7 time metadata.

Identifiers & web

URL Encoder

Percent-encode a URL component or full URI, decode it once, and inspect an absolute URL with ordered query parameters.

Text & data

3 tools
Text & data

Text Diff

Compare two blocks of plain text line by line and see exactly which lines were added, removed or left unchanged.

Text & data

Regex Tester

Test JavaScript regular expressions against sample text, inspect every match and its capture groups, and preview replace-all output.

Text & data

Markdown Previewer

Preview Markdown as live-rendered HTML right in your browser, then inspect or copy the generated HTML source code.

Built for real work

Quick should still be dependable.

Every utility states its scope and important limitations. That makes the result easier to check and safer to use.

01

Standards-aware

Where a format has a published standard, the page identifies the convention and avoids quietly guessing.

02

Private by design

Inputs stay in the current browser tab. The tools do not send pasted text or selected files to a server.

03

Useful context

Examples, edge cases and related tools sit beside the workspace so the page answers more than one narrow click.