Developer
Generate a valid SKILL.md for a Claude Agent Skill
Build a rules file for Cursor, GitHub Copilot or AGENTS.md
Encode text or files to Base64 and decode Base64 strings — instantly, in your browser.
Calculate Unix file permissions instantly — switch between octal (755), symbolic (-rwxr-xr-x) and a visual checkbox grid. Includes special bits (setuid, setgid, sticky).
Convert colours between HEX, RGB, HSL and CMYK — with live preview.
Pick colours and convert between HEX, RGB, HSL and CMYK — with CSS snippets ready to copy.
Build a cron schedule, or read one you already have
Generate CSS gradient code visually
Convert a docker run command to docker-compose.yml — handles ports, volumes, env, restart, networks.
Remove duplicate lines from any text instantly — case-sensitive, trimmed, sorted or unsorted.
Strip dot tricks, plus-aliases, and capitalisation to find the underlying email.
Generate favicons in all sizes from any image or text — download ready-to-use ICO, PNG and SVG files.
Find and replace text instantly — with regex support, case sensitivity and bulk replacements.
Build a JSON Schema for LLM tool/function calling (OpenAI · Anthropic)
Generate MD5, SHA-1, SHA-256 and SHA-512 hashes instantly — for passwords, files and data integrity.
Look up every HTTP status code instantly — with plain-English descriptions, use cases and fix tips.
Convert images to Base64 strings
Find your public IP address and look up any IP's location, ISP and organisation instantly.
Fix 文字化け and see any character in Shift_JIS, EUC-JP, ISO-2022-JP and UTF-8
Convert between JSON, YAML, XML, and CSV. Auto-detect input format, side-by-side editors, all client-side.
Format, validate and minify JSON instantly — with clear error messages and line numbers.
Generate a realistic sample JSON instance from a JSON Schema
Decode and inspect any JWT token instantly — header, payload, expiry and signature details, all in your browser.
Fix broken or truncated JSON that LLMs emit
Generate placeholder text instantly — paragraphs, sentences, words or bytes.
Type Markdown on the left, see HTML preview on the right. GitHub-flavored: headings, lists, tables, code blocks, task lists. In-browser, no signup.
Align and prettify Markdown tables, or convert CSV/TSV to Markdown
Build a valid MCP server entry for claude_desktop_config.json
Convert between binary, octal, decimal and hexadecimal — instantly.
Generate strong, random passwords with custom length and character rules.
Parse and format international phone numbers with libphonenumber. Country dropdown defaults to ASEAN.
Compare two prompts side by side and highlight what changed
Search, copy, and test regular expressions instantly.
Test and debug regular expressions in real time — with match highlighting, groups and a built-in reference.
Convert any title or phrase into a clean URL slug — for SEO, CMS and development.
Preview where an LLM stop sequence cuts generated text
Convert text to any case instantly — UPPER, lower, Title, camelCase, snake_case and more.
Split text into token-sized chunks with overlap for RAG
Encode and decode URLs and query strings instantly — with full RFC 3986 component support.
Decode browser, OS, device type, and bot signals from any User-Agent string.
Generate UUIDs v1/v4 and ULIDs instantly — bulk generation, multiple formats.
Remove extra spaces, tabs and blank lines from any text — clean messy copy-paste text instantly.
Browserbase
Cloud browsers, web APIs and agent tooling for AI agents
Google AI Studio
Google's free Gemini console; the strongest models are paid-only
Mintlify
Docs-as-code hosting with an AI Assistant, writing agent and MCP server
Recall.ai
One API for recordings, transcripts and metadata from any meeting
Vapi
Developer infrastructure for phone and web voice agents
A typing-test word is five keystrokes and real English words run longer
Typing tests count a word as any five keystrokes, the space included. Measured over two nineteenth-century nov...
MA
19 Oct
IBAN check digits catch every wrong digit and nearly every letter typo
An IBAN's check digits caught every wrong digit we typed into SWIFT's 89 example IBANs, and missed a few error...
KE
3 Oct
A Korean learner's dictionary needs only 1,465 of Hangul's syllables
Unicode encodes 11,172 Hangul syllables by one formula, and South Korea's 1987 character standard kept 2,350 o...
KE
3 Oct
The same Shift_JIS bytes read as 髙 or 騠, depending on the table
Browsers and Microsoft's CP932 table read Shift_JIS the same way, but other converters do not. We decoded all...
MA
3 Oct
Neither Chinese punctuation standard requires full-width marks
Mainland China's punctuation standard and Taiwan's handbook measure marks in character cells and never require...
MA
3 Oct
Phone number lengths across ASEAN's eleven members, from the regulators' own plans
How many digits follow the country code in each of ASEAN's eleven members, from the regulators' own numbering...
KE
3 Oct
The most common Chinese typos are homophones
Most Chinese typos are the right sound and the wrong character, picked from a pinyin keyboard's row of candida...
KE
27 Sep
What CSS ease and ease-in-out actually do
The default CSS easing, ease, is 80% of the way there at half the time, and it does not start from rest. We ev...
KE
27 Sep
What a seal script converter can and cannot do
Seal script got its own Unicode block on 16 September 2026 — 11,328 characters — and a converter will still le...
KE
25 Sep
Converting one passage between mainland, Taiwan and Hong Kong punctuation
Taiwan centres its full stops and the mainland puts them bottom left, yet it is the same character. Here is on...
KE
22 Sep
Why common Cantonese characters like 嘅 and 咗 could not be typed in Big5
Eleven of the most-used written Cantonese characters, including 嘅, 咗 and 喺, could not be typed in Big5, the...
KE
22 Sep
Why a Chinese character that works in GBK can break in Big5
GB2312, GBK and Big5 write the same Chinese character with different bytes, and none of them can write every c...
KE
21 Sep
Stripping the dots from an email address can merge two different people
Only Gmail's consumer domain and Proton document dots as ignorable. On Google Workspace dots change the addres...
KE
21 Sep
How Cangjie turns a Chinese character into five keystrokes
The 24 Cangjie keys are abstract shapes rather than the characters printed on them, and the five-code limit is...
EV
21 Sep
The payment QR on the counter is a line of text you can read
ASEAN merchant payment codes all use one published format: a flat string of tag, length and value. Decoding a...
KE
21 Sep
No ASEAN country has opened the whole 6 GHz band, and China opened none of it
Six ASEAN countries released the bottom 500 MHz of the 6 GHz band and stopped; the United States released all...
KE
19 Sep
127.0.0.1 is one of sixteen million loopback addresses
IPv4 reserved the whole of 127.0.0.0/8 for loopback, and the RFC that did it never names 127.0.0.1. Whether th...
KE
18 Sep
WCAG asks for 24 pixels, not the 44 everyone quotes
The 44-pixel tap target is quoted everywhere as the accessibility requirement. It is WCAG's Level AAA figure....
KE
16 Sep
Sixteen different base64 strings decode to the same byte
Base64 leaves four bits free when it encodes a single byte, and RFC 4648 binds encoders with MUST while granti...
KE
12 Sep
Z and +00:00 stopped being the same thing in 2024
RFC 9557 moved Z across to mean the instant is known and the local offset is not, while +00:00 kept its older...
KE
12 Sep
Valid JSON is not one thing, and three runtimes prove it
A fourteen-byte document containing a lone surrogate escape parses in Node, parses in Python and is refused by...
KE
12 Sep
The privacy header thousands of sites copied now guards something else
Permissions-Policy: interest-cohort=() was added in 2021 to opt out of FLoC. FLoC was cancelled, and Chromium...
PR
11 Sep
WebAuthn tells your server to ignore the bit that proves two factors
One flag distinguishes a passkey login that used only the device from one that also took a PIN or fingerprint....
KE
11 Sep
One embedding model, four different maximum lengths
The most downloaded sentence-embedding model ships four config files declaring 128, 256, 512 and 512 as its ma...
KE
5 Sep