Best Free Online Developer Tools to Use in 2026
A practical, opinionated list of the best free online developer tools worth using in 2026, organized by category so you can find what you need fast.
Aug 08, 2026
Convert text between UTF-8, UTF-16, and Latin1 encodings into hex, percent, decimal, or binary formats. Free, fast, and 100% client-side — no data ever leaves your browser.
Text encoding defines how characters are represented as bytes in computer systems. Different encodings use different byte sequences to represent the same text. Understanding encodings is essential for working with international text, APIs, databases, and file formats.
This tool supports three major encodings:
| Property | UTF-8 | UTF-16 | Latin1 (ISO-8859-1) |
|---|---|---|---|
| Bytes per character | 1 – 4 | 2 or 4 | 1 (always) |
| Character range | All Unicode (1.1M+) | All Unicode (1.1M+) | 256 characters only |
| ASCII compatibility | Yes (1 byte) | No (2 bytes + BOM) | Yes (1 byte) |
| BOM required | No (optional) | Optional (common) | No |
| Web usage (W3C) | Recommended | Legacy / internal | Legacy only |
| Typical use | HTML, JSON, APIs, files | Java, JS internals, .NET | Western European legacy |
Inspect raw byte values when an API returns garbled text or unexpected characters. Hex view reveals the exact encoding used.
Convert translated strings between encodings when migrating legacy databases or merging files from different systems.
Figure out why text appears as "é" or "’" — these are classic encoding mismatches this tool helps you identify and fix.
Encode CSV or SQL dump contents as hex to safely transfer between systems with different default encodings.
Examine URL-encoded or hex-encoded payloads to detect obfuscated injection attempts or hidden characters in logs.
Check the encoding of files or binary blobs to identify BOM markers, null bytes, or encoding signatures.
Mojibake from double-encoding
If text is encoded twice (e.g., UTF-8 bytes encoded as Latin1), you'll see garbled characters like "é". Decode once with the original encoding, then re-encode correctly.
BOM bytes in UTF-16
UTF-16 files often start with a Byte Order Mark (0xFF 0xFE for little-endian). This is normal but can cause issues when the BOM is treated as visible text.
Latin1 can't hold non-Western characters
Trying to encode Chinese, Arabic, or emoji into Latin1 will fail silently or produce ? replacement characters. Use UTF-8 for any non-ASCII text.
Percent-encoding vs URL encoding
Percent encoding in this tool encodes every byte. URL encoding typically leaves unreserved characters (A-Z, a-z, 0-9, - _ . ~) unchanged. For full URL encoding, use our dedicated URL Encoder/Decoder.
JavaScript (Browser)
const encoder = new TextEncoder();
const bytes = encoder.encode("Hello");
// Uint8Array [72, 101, 108, 108, 111]
const hex = [...bytes].map(b => b.toString(16).padStart(2, '0')).join(' ');
// "48 65 6c 6c 6f"
Python
# UTF-8 to hex
text = "Hello"
hex_str = text.encode("utf-8").hex(" ")
# "48 65 6c 6c 6f"
# Hex back to text
bytes_obj = bytes.fromhex(hex_str)
result = bytes_obj.decode("utf-8")
Node.js
const buf = Buffer.from("Hello", "utf-8");
console.log(buf.toString("hex"));
// "48656c6c6f"
Encoding transforms data into a different format for interoperability (like UTF-8 bytes or hex), while encryption secures data so it cannot be read without a key. Encoding is reversible without a key and is not designed for security.
Different encodings represent the same characters using different byte sequences. For example, the character "é" is one byte (0xE9) in Latin1 but two bytes (0xC3 0xA9) in UTF-8. This tool lets you compare how the same text looks in different encodings.
You can view encoded bytes in four formats: Hex (48 65 6C), Percent (%48%65%6C, URL-style), Decimal (72 101 108), and Binary (01001000 01100101 01101100). All formats are space-separated for readability.
Yes. All processing happens entirely in your browser using JavaScript's built-in TextEncoder and TextDecoder APIs. Your data is never uploaded to any server, stored, or logged.
Mojibake happens when bytes encoded in UTF-8 are misinterpreted as Latin1 (or vice versa). Paste the garbled text here, try decoding with each encoding, and pick the one that produces readable output. The most common fix is re-encoding: decode as Latin1, then re-encode as UTF-8.
Encode and decode Base64 strings
Encode and decode URL strings
Encode/decode HTML entities
Convert domain names to/from Punycode
Encode/decode text in various formats
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