Supporting
Developer tools
Not the homepage story — India financial tools are. These exist so the same local-compute rule applies to tokens, hashes, and subnet math. Paste a JWT or a CIDR into the header search and it will steer you here.
When to use this shelf
Decode a token without jwt.io's trust boundary. Hash a string without a pastebin. Check whether 10.0.0.0/16's broadcast is what you think. Look up 429 without opening MDN. Generate favicon PNGs without uploading a logo to a random converter. Diff two JSON blobs without piping them through an online "compare tool" that logs the request.
Methodology — what runs where
Everything on this shelf executes with the Web Crypto API, native atob/btoa, canvas, or small hand-written parsers — no server round-trip for the actual computation. The JWT decoder splits the token on ., base64url-decodes the header and payload, and pretty-prints the JSON; it deliberately does not verify a signature, because verification needs the issuer's key and this tool has no way to know if that key is trustworthy. The hash generator wraps CryptoJS's MD5/SHA1/SHA256 implementations and never sends the input anywhere. The CIDR calculator does bitwise arithmetic on the 32-bit integer representation of an IPv4 address to derive network, broadcast, and usable host range — the same math a subnet cheat-sheet walks through by hand, just faster.
Worked example
Paste 10.0.0.0/22 into the CIDR calculator: it reports a /22 as 1,024 total addresses, network address 10.0.0.0, broadcast 10.0.3.255, and a usable host range of 10.0.0.1–10.0.3.254 (1,022 usable hosts once network and broadcast are excluded). That is the same answer you'd get walking through the math with a subnet chart, minus the chart.
Honesty
"Client-side" is a claim about our servers, not about every browser extension on your laptop. A malicious extension can still read the DOM regardless of what this page promises. Production customer tokens, real API keys, and live credentials still do not belong in screenshots, Slack threads, or "quick checks" on a shared machine — decode them here, then close the tab.
| Tool | Job |
|---|---|
| IPv4 / CIDR calculator | Free IPv4 CIDR / subnet calculator: network address, broadcast, subnet mask, wildcard, and usable host range. Updates as |
| HTTP status codes | Quick reference for common HTTP status codes and names. Search 301, 404, 429, 500, 503 and more. Links the official HTTP |
| Favicon generator | Create favicon PNG sizes from an uploaded image on a canvas in your browser. Download the set locally — no third-party u |
| JWT decoder | Decode a JSON Web Token header and payload in your browser. Signature bytes are shown, not verified. Prefer this over pa |
| JWT generator | Create unsigned or HMAC-signed JWTs for local testing. Never paste production secrets into a browser page. Token math st |
| Hash generator | Hash text with MD5, SHA-1, or SHA-256 entirely in-page. Useful for file checksums and digests — not for storing password |
| Base64 / URL / HTML encoder | Encode or decode Base64, URL components, and HTML entities in your browser. Encoding is not encryption — ciphertext this |
| JSON / YAML / XML formatter | Pretty-print and validate JSON, YAML, and XML in your browser. Invalid documents get pointed errors without a server rou |
| UUID generator | Generate UUID v4 identifiers with browser cryptography. Fine for random IDs; check your threat model before using them a |
| Regex tester | Test JavaScript-flavored regular expressions with live match groups as you type. Great for debugging — catastrophic back |
| Color picker | Pick a color and convert between HEX, RGB, and HSL locally. Handy for design QA without uploading brand palettes to a Sa |
| Timestamp converter | Convert Unix epoch seconds or milliseconds to readable dates and back, using your browser timezone. Free online timestam |
| Cron visualizer | Paste a cron expression, see what it means, and preview upcoming fire times. Note Vixie vs Quartz dialect differences be |
| Password generator | Generate strong passwords with length and charset controls using browser randomness. Store them in a password manager — |
| QR code generator | Create QR codes locally for URLs, plain text, or Wi-Fi join strings. Scan before you print a poster. Generation stays in |
| Text / JSON diff | Compare two text or JSON blobs and highlight differences in your browser. Useful for config drift without uploading to a |
| Markdown converter | Convert Markdown to HTML with live preview in your browser. Renderer libraries may load from a file host; your document |
| Secure notes | Encrypt and decrypt text with a passphrase using AES-GCM in your browser. If you forget the passphrase, the ciphertext i |
Looking for JSON, JWT, CIDR, or an India ID by type? Use search, or the footer link “Browse by format.”