Notoo Tools

Free developer tools

16 fast, private utilities that run entirely in your browser — no login, no server, nothing leaves your device. Each one is its own bookmarkable page, alongside the full Notoo workspace of notes, code, documents, drawings and markdown.

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Data

JSON FormatterFormat, minify and validate JSON. Pretty-print with 2-space indent or collapse to a single line, with instant error reporting.JWT DecoderDecode a JSON Web Token into its header and payload and read the claims, with human-readable expiry and issued-at times.

Encoding

Base64 Encode / DecodeEncode text to Base64 or decode it back, with UTF-8 support and a URL-safe variant.Hash GeneratorGenerate SHA-1, SHA-256, SHA-384, SHA-512 and MD5 hashes of any text, computed locally in your browser.

Generators

UUID GeneratorGenerate one or many random v4 UUIDs, with nil-UUID and uppercase options. Copy or download the list.QR Code GeneratorTurn any text or URL into a QR code and download it as a PNG.Lorem Ipsum GeneratorGenerate placeholder paragraphs, sentences or words of lorem ipsum text.Markdown Table GeneratorPaste CSV or TSV, or fill a grid, and get a clean GitHub-flavored Markdown table.

Text

Case ConverterConvert text between camelCase, snake_case, kebab-case, PascalCase, CONSTANT_CASE, Title Case and more.Text DiffCompare two blocks of text and see a colored, line-by-line diff of what changed.Regex TesterTest a regular expression against sample text with live match highlighting and capture groups.

Time

Unix Timestamp ConverterConvert between Unix timestamps and human dates, in seconds or milliseconds, ISO and local time.Cron Expression ParserExplain a cron expression in plain English and preview its next scheduled run times.

Web

cURL to fetchPaste a cURL command and get equivalent JavaScript fetch() code you can drop into your app.Color ConverterConvert colors between HEX, RGB and HSL, preview them, and check WCAG contrast.

Media

Image Resizer & CompressorResize and compress images entirely in your browser and download the smaller result.

Frequently asked

Are these developer tools free?
Yes. Every tool on Notoo Tools is completely free, with no account, sign-up or usage limits.
Is my data private?
Yes. Every tool runs entirely in your browser. Nothing you type is uploaded — there is no server that receives your input, so your data never leaves your device.
Do the tools work offline?
Once the page has loaded, the tools compute locally and keep working without a network connection.
How many tools are there?
Notoo currently ships 16 tools across 7 categories — data, encoding, generators, text, time, web and media.