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 | IPv4 subnet math: network, broadcast, mask, wildcard, usable hosts. Updates as you type. |
| HTTP status codes | Search common HTTP status codes and names. Quick reference after the page loads. Links the official HTTP Semantics guide |
| Favicon generator | Upload an image, generate common favicon PNG sizes on a canvas, download locally. No upload farm. |
| JWT decoder | Decode JWT header and payload in your browser. Signature is shown, not verified against secrets you should not paste. |
| JWT generator | Create unsigned or HMAC-signed JWTs for local testing. Never use production secrets in a browser page. |
| Hash generator | Hash text with common digests entirely in-page. Useful for checksums; not for storing passwords without a proper KDF. |
| Base64 / URL / HTML encoder | Encode or decode Base64, URL components, and HTML entities locally. Encoding is not encryption. |
| JSON / YAML / XML formatter | Pretty-print and validate JSON, YAML, and XML in your browser. Invalid docs get pointed errors without a round trip. |
| UUID generator | Generate UUID version 4 identifiers using browser randomness. Fine for IDs; not a substitute for secrets with enough ent |
| Regex tester | Test JavaScript-flavored regular expressions with live matches. Great for debugging; catastrophic backtracking can still |
| Color picker | Pick and convert colors between HEX, RGB, and HSL locally. Handy for design QA without uploading brand palettes. |
| Timestamp converter | Convert Unix epoch seconds/milliseconds to human-readable dates and back, in your timezone context. |
| Cron visualizer | Explain cron expressions and preview upcoming fire times. Quartz vs Vixie differences still apply — read the dialect not |
| 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. |
| Text / JSON diff | Compare two blobs and highlight differences in your browser. Useful for config drift without uploading to a SaaS diff to |
| Markdown converter | Convert Markdown to HTML with live preview. The libraries that render it may load from an outside file host; your docume |
| Secure notes | Encrypt and decrypt text with a passphrase using AES-GCM in the browser. If you forget the passphrase, the ciphertext is |
Looking for JSON, JWT, CIDR, or an India ID by type? Use search, or the footer link “Browse by format.”