Online Decoder and Encoder
An online encoder decoder transforms data between plain text or binary formats and standardized representation schemes — such as Base64, URL percent-encoding, HTML entities, or Hex — enabling safe data transmission over text-based network protocols, APIs, and web rendering pipelines.
Select your encoding format (Base64, URL, HTML, Hex, Binary, Octal, or GZIP), choose Encode or Decode mode, and type or paste your input. ScanSuite converts your data in real time with bidirectional mode switching, drag-and-drop file support, and instant output copy buttons.
Introduction to Data Encoding and Decoding
Data encoding transforms raw text or binary data into specialized character sets to ensure compatibility with network protocols, web browsers, databases, and serialization formats. Decoding reverses the transformation to restore the original unencoded data.
ScanSuite's free multi-format encoder decoder supports Base64, URL percent-encoding, HTML entity escaping, Hexadecimal, Octal, Binary representations, and GZIP compression directly in your browser. With instant bidirectional conversion and client-side execution, you can debug payloads and prepare data safely without server hops.
What Is an Online Encoder Decoder?
An encoder decoder is a utility that applies encoding algorithms (like Base64 RFC 4648 or URL RFC 3986) to translate input strings or files into safe transfer encodings and back. Unlike encryption, encoding does not require a secret key and is not intended for secrecy — its sole purpose is data format transportability.
Common encoding types address distinct technical hurdles: Base64 converts binary media into 64 safe ASCII characters for JSON or email transfer; URL encoding converts reserved characters like `?`, `&`, and spaces into `%XX` hex sequences for HTTP query strings; HTML encoding escapes `<` and `>` to prevent cross-site scripting (XSS).
Why Use an Online Encoding Tool?
Developers working on API integration, web security, and frontend engineering frequently encounter encoded strings in HTTP headers, OAuth authorization codes, JWT payloads, and database records.
Instead of writing custom scripts or running CLI commands like `base64` or `python -c "import urllib.parse..."`, our browser-based tool offers an all-in-one workspace with real-time format detection, file upload support, and clean visual formatting for rapid troubleshooting.
Who Uses Encoder Decoders?
Web developers use URL and HTML encoders to construct safe query parameters and sanitize user input before DOM injection.
API developers and backend engineers decode Base64 authorization headers, basic auth credentials, and serialized webhook payloads.
Security researchers and penetration testers inspect obfuscated strings, decode web shell payloads, and test input handling against encoding bypasses.
How Encoding Schemes Work Under the Hood
Base64 encoding takes 24 bits of input data (3 bytes) and splits them into four 6-bit chunks. Each 6-bit index maps to an ASCII character in the Base64 alphabet (`A-Z`, `a-z`, `0-9`, `+`, `/`), using `=` for trailing byte padding.
URL encoding replaces non-ASCII or reserved characters with a percent sign `%` followed by two hexadecimal digits representing the character's UTF-8 byte value. HTML encoding replaces special characters like `&`, `<`, `>`, `"`, and `'` with named entities like `&` and `<` or numerical codes.
Base64
Base64 maps bytes to a 64-character alphabet so binary data can travel in text. Input Hi becomes SGk=.
URL
URL encoding percent-encodes characters that are not safe in a query string. Input a b&c becomes a%20b%26c.
HTML
HTML entity encoding replaces <, >, and & so a browser shows them as text. Input <b> becomes <b>.
Hex
Hexadecimal writes each byte as two hex digits. Input Hi becomes 4869.
ASCII Hex
ASCII hex is the same byte-to-hex conversion aimed at readable characters. Input A becomes 41.
Octal
Octal writes each byte in base 8. Input A becomes 101.
Binary
Binary writes each byte as eight bits. Input A becomes 01000001.
Gzip
Gzip compresses the text and then shows the result as Base64 so you can paste it. Decode expects that Base64 string.
Decode a JWT
A JWT is three Base64URL segments, not a general encoding. Use the JWT debugger at /tools/jwt-debugger/ to read the header and payload.
Encoding Scheme Comparison
| Format | Alphabet / Output Set | Size Overhead | Primary Use Case | |
|---|---|---|---|---|
| Base64 | 64 ASCII chars (A-Z, a-z, 0-9, +, /) | +33% growth | Embedding binary in text (JSON, email, CSS) | |
| URL Encoding | ASCII + %XX hex tuples | Variable (3x for special chars) | HTTP GET parameters and URI components | |
| HTML Entities | ASCII + &name; / &#code; | Variable | Preventing XSS in web page rendering | |
| Hexadecimal | 16 chars (0-9, a-f) | +100% growth (2 hex per byte) | Debugging binary data, hashes, memory dumps | |
| GZIP + Base64 | Compressed binary → Base64 | Reduced size for large text | Transmitting large payloads over JSON APIs |
Why Does My Base64 Decoding Fail with an Invalid Character Error?
Base64 strings must only contain valid characters (`A-Z`, `a-z`, `0-9`, `+`, `/`, and `=`). Whitespace, newlines, or URL-safe characters (`-` and `_`) will trigger decode errors unless stripped or normalized.
Related tools
- JWT Debugger — Decode & verify JWT tokens
- URL Parser — Parse & analyze URLs
- Hash Generator — Calculate MD5, SHA-256, and SHA-512 cryptographic digests.
- JWT Debugger — Decode and inspect JSON Web Tokens.
- URL Parser — Parse and break down complex web URLs.
- QR Code Generator — Generate custom QR codes from encoded strings.
- SRI Generator — Generate Base64 Subresource Integrity hashes.
Frequently Asked Questions
How do I decode text online?
Pick the format your text is in (Base64, URL encoding, HTML entities or Hex), paste the text and choose Decode. If you are not sure of the format, there are clues. Base64 uses A–Z, a–z, 0–9, + and / and often ends with `=`. URL encoding has `%20`-style sequences. HTML entities look like `&`.
What does online encoding mean?
Encoding converts data into another representation so it can be safely stored or sent. Base64, for example, turns binary data into text, and URL encoding makes characters safe to use in a link. It is reversible by anyone and is not encryption, so it does not protect secrets.
What's the difference between encoding, encryption and hashing?
Encoding changes the format and anyone can reverse it. Encryption hides data and needs a key to reverse. Hashing produces a fixed-length fingerprint and cannot be reversed. Use this tool for encoding, the hash generator for hashes and the hash identifier to recognise one.
Can this encoder decode JWT tokens?
A JWT is three Base64URL-encoded parts separated by dots. Use the JWT debugger to decode the header and payload and to inspect claims. This encoder/decoder does not include a Base64URL format option.
Why does my Base64 decode show garbled text?
The data is probably binary (an image or a compressed file) rather than text, uses a different character encoding, or is Base64URL (which uses `-` and `_` instead of `+` and `/`). Convert Base64URL to standard Base64 first, or decode JWTs with the JWT debugger.
How does Base64 encoding work?
Base64 converts 3 bytes of binary data (24 bits) into 4 printable ASCII characters by mapping 6-bit chunks to a 64-character index table. Padding with `=` makes the length a multiple of four.
What is the difference between encoding and encryption?
Encoding transforms data into a standard public format for compatibility, requiring no key to decode. Encryption transforms data into unreadable ciphertext to ensure secrecy, requiring a secret key to decrypt.
Why is URL encoding necessary?
URLs can only contain a limited set of unreserved ASCII characters. Characters like spaces, question marks, and ampersands have special structural meaning and must be percent-encoded to avoid syntax ambiguity.
What are HTML entities?
HTML entities are special code sequences (like `<` for `<`) used by web browsers to display characters that would otherwise be parsed as HTML markup tags.
What is a Data URI?
A Data URI allows inline embedding of small files (like images or fonts) directly into HTML or CSS using the format `data:[mediatype];base64,[data]`.
Does Base64 encoding increase file size?
Yes, Base64 encoding increases file size by approximately 33% because 3 raw bytes expand into 4 ASCII characters.
What is URL-safe Base64?
URL-safe Base64 (Base64URL) replaces `+` with `-` and `/` with `_`, and omits trailing `=` padding characters so the string can be safely used in web addresses without percent-encoding.
Are my inputs sent to your server when encoding or decoding?
No. All conversion algorithms run completely in your client browser memory using local JavaScript APIs.
Can I encode binary files like images or PDFs?
Yes. You can drag and drop any file into the tool to generate Base64 strings or decode Base64 back into downloadable binary files.
What is GZIP compression encoding?
GZIP compression compresses text input using Deflate algorithm before Base64 encoding, drastically reducing payload size for large JSON or XML strings.
Why does Base64 output end with equals signs (=)?
The `=` sign is padding used when the input byte length is not divisible by 3, ensuring the output string aligns to 4-character blocks.
What happens if I try to decode invalid Base64 input?
The tool detects invalid characters or bad block lengths and displays an intuitive error message explaining the issue.
What is Hex encoding?
Hex (hexadecimal) encoding represents each byte of input data as two 4-bit hexadecimal digits from `00` to `FF`.
How do I decode Basic Authentication headers?
Basic Auth headers take the format `Basic [base64_string]`. Paste the Base64 portion into the decoder to reveal the `username:password` string.
Is this encoder decoder tool free with no limits?
Yes, ScanSuite provides unlimited free encoding and decoding without registration or rate caps.
Can I convert between Hex and Base64 directly?
Yes. Switch your selected format to Hex or Base64 to convert binary byte representations instantly.
What is Unicode UTF-8 encoding support?
Our tool natively supports full multi-byte UTF-8 string encoding, handling emojis, international alphabets, and special symbols correctly.
Which format should I use to sanitize user input in HTML?
Use HTML Entity encoding to escape `<` and `>` characters before inserting user text into HTML templates.
What is an online encoder?
An online encoder turns text or bytes into another text form, such as Base64 or URL encoding, so the value can travel through a form, a URL, or a JSON field. Use decode to reverse it. Do not use encoding to hide a secret.
Summary
ScanSuite's free online encoder decoder converts text and files across Base64, URL percent-encoding, HTML entities, Hex, Binary, Octal, and GZIP compression. With instant bidirectional mode switching and local client-side processing, developers can debug payloads and prepare data effortlessly.