Free Online Coding Tools
Free online coding tools for developers — format and minify code, generate hashes, decode JWTs, encode HTML entities, and more.
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Coding Tools is this site's largest category — every developer-focused utility that doesn't need a specific file type like an image or PDF. That spans code formatters and minifiers for JSON, CSS, HTML, and JavaScript; a JSON tree viewer for exploring nested data; an HTML entity encoder/decoder; a JWT encoder/decoder; cryptographic hash generators from MD5 through SHA-512; a QR code generator; and a secure password generator. Every one of them runs entirely client-side, using JavaScript already built into your browser — nothing you paste, type, or generate is ever sent to a server, which matters if you're working with real credentials, API responses, or proprietary code. Formatters and generators that produce their own executable code are grouped under "Code Formatters" below; the rest — hashes, JWTs, QR codes, passwords — sit alongside them in this same broader category. The visual CSS generators (gradients, loaders, patterns, and the like) have their own dedicated CSS Tools category.
Tools in this category
CSS Formatter
Format, beautify, and minify CSS instantly in your browser.
HTML Encoder/Decoder
Encode plain text to HTML entities or decode HTML entities back to plain text.
HTML Formatter
Format, beautify, and minify HTML instantly in your browser.
JavaScript Formatter
Format, beautify, and compress JavaScript instantly in your browser.
JSON Formatter
Format, validate, and beautify JSON instantly in your browser.
JSON Tree Viewer
Browse pasted JSON as an interactive, expandable tree instead of a flat text block.
JWT Encoder/Decoder
Decode JSON Web Tokens instantly to see their Header and Payload, verify HMAC signatures, or encode a brand new JWT — all in your browser.
MD5 Hash Generator
Generate an MD5 hash from any text instantly, plus an honest reverse-lookup search against common passwords.
Password Generator
Generate strong, random passwords locally using a cryptographically secure random number generator.
QR Code Generator
Generate a QR code from any text or URL instantly, entirely in your browser.
SHA-1 Hash Generator
Generate a SHA-1 hash from any text instantly, with an honest reverse-lookup search against common passwords.
SHA-224 Hash Generator
Generate a SHA-224 hash from any text instantly, with an honest reverse-lookup search against common passwords.
SHA-256 Hash Generator
Generate a SHA-256 hash or checksum from any text instantly, with an honest reverse-lookup search against common passwords.
SHA-384 Hash Generator
Generate a SHA-384 hash from any text instantly, with an honest reverse-lookup search against common passwords.
SHA-512 Hash Generator
Generate a SHA-512 hash from any text instantly, with an honest reverse-lookup search against common passwords.
Frequently asked questions
- Do these tools upload or store my code, hashes, or generated output anywhere?
- No. Every coding tool in this category runs entirely in your browser using JavaScript. Your code, text, or generated output is never transmitted to a server, logged, or stored.
- What's the difference between "Code Formatters" and the rest of Coding Tools?
- Code Formatters (JSON/CSS/HTML/JavaScript) all do the same job — pretty-print or minify a specific language's syntax. The rest of this category covers other developer needs that aren't language-syntax formatting: generating a hash, decoding a JWT, generating a QR code or password, and so on.
- Are the hash generators reversible — can they "decrypt" a hash?
- No, and this is worth being explicit about. A cryptographic hash cannot be mathematically reversed. The reverse-lookup feature on each hash generator only works by checking a hash against a bundled dictionary of common words — it succeeds only if the original text was something common, and is honestly described as a lookup, never as decryption.
- Is the password generator actually secure?
- Yes — it uses `crypto.getRandomValues()` exclusively (rejection- sampled, Fisher-Yates shuffled), never `Math.random()`, which is not cryptographically secure. Nothing about a generated password is sent anywhere or logged.
- Can I use the generated CSS, QR codes, or other output commercially?
- Yes. Everything generated by these tools — CSS code, QR code images, gradients — is plain output with no license restriction and no attribution required, for personal, client, or commercial use.