Encoding Tools
Encode and decode Base64, Base32, Base58, URLs, HTML, hex and more, inspect bytes and data URIs, and fix line endings — all on your device. Learn more
Base32 Encoder/Decoder
RFC 4648 Base32 encoding, both directions.
Base58 Encoder/Decoder
Bitcoin-style, no look-alike characters.
Base64 Encoder/Decoder
Encode text to Base64, or decode it back.
Base64URL (JWT-safe)
URL and filename-safe variant.
Base85/Ascii85 Encoder/Decoder
PostScript/PDF-style encoding.
Data URI Parser
Inspect a data: URI's contents.
Escape-Sequence Converter
\n \t \xNN, both directions.
Hex String ↔ Text
Bytes as hex, or back to text.
HTML Encoder/Decoder
Escape text so it's safe to embed as HTML.
Image to Base64/Data URI
Convert an image to an embeddable data URI.
Line-Ending (CRLF/LF) Converter & Detector
Detect and convert between CRLF, LF and CR line endings
MIME Type ↔ Extension Lookup
Search by extension or MIME type.
Number Base Converter
Binary, decimal, hex and octal, live.
PEM ↔ DER Converter
Certificate encodings, converted freely.
Punycode Converter
International domain names to/from Punycode.
Quoted-Printable Encoder/Decoder
The email-friendly MIME encoding.
ROT47 Cipher
Rotation cipher covering all printable ASCII.
URL Encoder/Decoder
Percent-encode text for safe use in a URL.
UTF-8 Byte Viewer
See the raw bytes behind any text.
Encode, decode and inspect data without installing anything
Encoding turns data into a form that survives the journey, whether that's a URL, an email, a JSON file or a web page. The Base64 Encoder/Decoder handles the format you'll meet most, with full Unicode support so accents and emoji survive the round trip. Its cousin Base64URL is what JSON Web Tokens use. For specialist jobs there's Base32 (the format behind two-factor authentication secret keys), Base58 (as used in Bitcoin addresses) and Ascii85 from PostScript and PDF.
Building for the web? The URL Encoder makes text safe for query strings. The HTML Encoder stops < and & from breaking your markup. Image to Base64 turns a small icon into a data URI you can paste straight into CSS, and the Data URI Parser shows what's inside one. The MIME Type Lookup answers "what Content-Type should this file have?", and the Punycode Converter shows how an international domain such as münchen.de really looks on the wire.
For lower-level work, the UTF-8 Byte Viewer and Hex ↔ Text converter show the raw bytes behind any string. The Number Base Converter moves between binary, octal, decimal and hex, and stays exact even for huge numbers. The Escape-Sequence Converter prepares text for code strings, and the Line-Ending Detector sorts out Windows-versus-Unix line-break problems. Email developers get a Quoted-Printable converter, and certificate work is easier with the PEM ↔ DER Converter. Everything runs in your browser, so tokens, keys and certificates never leave your device.
Questions and answers
- What's the difference between Base64 and Base64URL?
- They encode data the same way, but standard Base64 uses + and / and pads the end with =. All three characters have special meanings in web addresses. Base64URL swaps them for - and _ and drops the padding, so the result can sit in a URL or file name untouched. JSON Web Tokens use Base64URL. The Base64 decoder here accepts both forms.
- Should I use the URL Encoder or the HTML Encoder?
- It depends where the text is going. The URL Encoder percent-encodes text for web addresses (a space becomes %20), which is what you need for query-string values. The HTML Encoder turns <, >, & and quote marks into entities (< and so on), so text shows up on a web page instead of being read as markup. Using one where you need the other will break things in subtle ways.
- Is Base64 or ROT47 a form of encryption?
- No. Base64, Base32, Base58, Ascii85 and hex are encodings: anyone can reverse them instantly, with no key. ROT47 only shuffles characters, so it's light obfuscation at best, useful for hiding a spoiler or puzzle answer from a casual glance. To keep data secret, use a real cipher from the Encryption tools instead.
- Why does the UTF-8 Byte Viewer show more bytes than I have characters?
- UTF-8 stores plain English letters, digits and common punctuation in one byte each. Accented letters take two, most other alphabets take two or three, and emoji take four. The Byte Viewer and Hex ↔ Text converter show exactly which bytes each character becomes. That's useful when a system complains about length or shows garbled characters such as "é" in place of "é".
- When should I inline an image with Image to Base64 instead of linking to the file?
- Inline only small images such as icons, tiny logos or simple backgrounds, where saving a separate download is worth more than the size cost. Base64 makes a file about a third bigger, and an inlined image can't be cached separately. For anything larger than a few kilobytes, link to the file instead. The Data URI Parser lets you check what an existing inlined image contains.