Free Online Data Converters

Developers constantly move data between representations: an API wants Base64, a URL needs percent-encoding, a log file shows a Unix timestamp, a debugger prints raw hex. These converters handle the round trips instantly — encode or decode Base64 (including the URL-safe variant used in JWTs), percent-encode or decode a URL with one toggle instead of two separate pages, translate between binary and hexadecimal, turn JSON objects into query strings and back, and convert epoch timestamps into readable dates.

All conversions happen locally in your browser with standard JavaScript APIs, so tokens, credentials, and production data stay on your machine. No uploads, no rate limits, no sign-up — just paste, convert, and copy the result.

All Converters Tools (16)

Epoch Timestamp Converter

Convert Unix epoch timestamps to human dates and back — seconds or milliseconds, UTC and local time, with a live clock. Free and 100% client-side.

Launch Tool

Cron Expression Parser

Parse any cron expression into plain English and preview its next five run times instantly — debug crontab schedules with confidence. Free, client-side.

Launch Tool

Base64 Encoder/Decoder

Encode text to Base64 or decode Base64 strings back to plain text instantly. Free, client-side converter that handles JWT payloads and data URIs.

Launch Tool

URL Encoder

URL encode any string, or flip to decode — converts spaces, special characters, and Unicode into percent-encoded URI format instantly. Free, client-side.

Launch Tool

URL Decoder

Decode percent-encoded URLs back to plain text, or flip to encode — converts %20, %26, %3D and all URI escape sequences instantly. Free, client-side.

Launch Tool

Base64 URL Safe Encoder

Encode text to URL-safe Base64 — replaces + with - and / with _ so output is safe in URLs and JWT tokens. Free, instant, client-side encoder.

Launch Tool

Binary to Hex

Convert a binary stream to hexadecimal instantly — every 4 bits become one hex digit, whitespace ignored. Free, client-side binary to hex converter.

Launch Tool

Hex to Binary

Convert hexadecimal to a binary stream instantly — every hex digit expands to 4 binary bits, clearly grouped. Free, client-side hex to binary tool.

Launch Tool

JSON to URL Params

Convert a flat JSON object into a URL query string instantly — build parameter strings for GET requests and APIs. Free, instant, and client-side.

Launch Tool

URL Params to JSON

Parse a URL query string into a formatted JSON object instantly — inspect GET parameters and form data at a glance. Free, instant, client-side.

Launch Tool

Unix Time to Date

Convert Unix timestamps (whole or fractional seconds, and milliseconds) to readable dates instantly — paste one value or a whole list, one per line. Free, client-side.

Launch Tool

Text to SQL IN

Format a list of values into a quoted SQL IN() clause instantly — with single quotes escaped safely. Free, client-side SQL IN list generator.

Launch Tool

URL Parser

Paste a full URL and instantly see its protocol, host, port, path, every query parameter, and hash — all broken out separately. Free, client-side URL parser.

Launch Tool

cURL Command Builder

Build a properly-escaped curl command from a method, URL, headers, and body — no more hand-quoting shell syntax. Free, client-side curl builder.

Launch Tool

Image to Base64 Converter

Convert an image to a base64 data URI, or decode a base64 string back into an image — entirely in your browser. Free, client-side, nothing is ever uploaded.

Launch Tool

Markdown to HTML Converter

Convert Markdown to HTML, or HTML back to Markdown — supports headings, lists, links, code blocks, tables, and more. Free, instant, client-side converter.

Launch Tool

Frequently Asked Questions

Do the URL Encoder and Decoder work both ways?
Yes — each page has a toggle to switch between encoding and decoding without leaving the tool, so one bookmark covers both directions.
What's the difference between Base64 and Base64 URL-safe?
Standard Base64 uses + and / which aren't safe inside URLs; the URL-safe variant swaps those for - and _ and drops padding — the format JWTs and URL query parameters use.

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