Free online tools, built small and sharp
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Util123 online tools
JSON Formatter →
Format, validate, highlight, tree view, search, sort keys, auto-fix, convert to YAML/CSV/XML, diff, JSONPath.
util123.top/jsonTimestamp Converter →
Unix timestamp ↔ date, auto-detects seconds / milliseconds, shows UTC, ISO 8601 and relative time.
util123.top/timestampBase64 Encoder →
Text ↔ Base64 with full UTF-8 support, URL-safe variant and file-to-Base64.
util123.top/base64Password Generator →
Strong random passwords with custom length and character sets, live strength, entropy and combination count.
util123.top/passwordQR Code Generator →
Turn text, links or Wi-Fi info into downloadable QR codes with adjustable size, error correction and colors.
util123.top/qrcodeHash Generator →
MD5, SHA-1, SHA-256 and SHA-512 digests of text or files, copyable in upper or lower case.
util123.top/hashURL Encoder →
Percent-encode / decode URLs, component or full-URL mode, and split query strings into a table.
util123.top/urlBase Converter →
Binary, octal, decimal and hex conversion in real time, with big numbers and 0x / 0b / 0o prefixes.
util123.top/radixUnit Converter →
Length, weight, temperature and data storage — type one value, see every unit at once.
util123.top/unitColor Converter →
HEX, RGB, HSL and HSV conversion with eyedropper, palettes and contrast preview.
util123.top/colorCase Converter →
UPPER, lower, Title Case, plus camelCase, snake_case and kebab-case renaming.
util123.top/caseWord Counter →
Live characters, words, lines and bytes — plus CJK character count for mixed text.
util123.top/counterLorem Ipsum →
Placeholder text by paragraph, sentence or word — for mockups, design drafts and layout tests.
util123.top/loremRandom Number →
Random integers in a range, dice rolls, or pick a winner from a list of names.
util123.top/randomRegex Tester →
Live match highlighting, capture groups and positions, common patterns built in, replace preview.
util123.top/regexUUID Generator →
Bulk UUID v4 from secure randomness, with uppercase, no-hyphen and braces options.
util123.top/uuidMy IP →
See your public IP, geolocation and ISP, and look up any IPv4 / IPv6 address's ASN.
util123.top/ipSubnet Calculator →
IP + mask (CIDR or dotted) → network / broadcast address, usable host range and host count.
util123.top/subnetFAQ
- What is Util123?
- Util123 is a collection of free online tools — JSON formatter, Unix timestamp converter, Base64 encoder, password generator, QR code maker, hash generator, UUID generator, unit converter and more. Each tool does one thing and does it well.
- Do I need to sign up or pay?
- No. Every tool is free to use, with no registration, login, or browser extension required.
- Is my data uploaded to a server?
- No. All processing happens locally in your browser. The text, files and values you paste never leave your device.
- Does it work on mobile?
- Yes. Every tool page is fully responsive and works in mobile browsers.
- Will more tools be added?
- Yes. New tools are added steadily, following one rule: small, sharp, and genuinely useful — no feature bloat.