About

ToolSharp.dev is a small collection of developer utilities — JSON, JWT, regex, cron, connection strings, and more — built to run entirely in your browser. No signup, no account, nothing you paste ever reaches a server.

// why this exists

Most of the "paste your JSON here" sites out there bury the actual tool under a signup wall, an account system, or a page so cluttered with ads that finding the input box takes longer than fixing the JSON would've. ToolSharp.dev started as a fix for that annoyance: one tool, one page, the input box front and center, and an answer in the time it takes to paste.

The actual spark was narrower than that: the auto-fix engine behind the JSON formatter. Malformed JSON is rarely broken in just one obvious way — a comma's missing, a key lost its quotes and its colon along with them, a trailing comma slipped in, an invisible Unicode space snuck in from a copy-paste, someone left a comment in what's supposed to be strict JSON. A regex substitution doesn't fix any of that reliably. It takes an actual token-by-token repair pass that understands JSON's grammar well enough to tell "this is a key that lost its quotes and happens to contain a space" apart from "this is a key with a missing colon before its value" — two situations that look identical until you look one token further ahead. Getting that repair engine right, and still refining it whenever a real edge case turns up, is what grew into the rest of the site.

// what's here

The tools section covers the small, recurring tasks backend and full-stack developers hit constantly — formatting and validating JSON, decoding a JWT, building a SQL Server connection string, testing a regex, converting a cron expression to plain English, diffing two blobs of text, and more. The guides section goes deeper on the specific errors and gotchas that send people searching in the first place — things like why JSON.parse throws "Unexpected end of JSON input," or what changed in a specific EF Core or SQLite release that broke a working migration.

// how it's built

Every tool runs client-side — plain JavaScript, no framework, no backend processing your input. What you type or paste stays in your browser. The one exception, share-pad's optional code-sharing mode, is explicit about the one thing it does send (encrypted, never plaintext) — covered in full in the privacy policy.

// who's behind it

ToolSharp.dev is built and maintained by one developer, in the same spirit as the tools it offers: no team, no funding round, just something useful kept working and added to over time. Found a bug, want a tool or guide added, or have feedback? The contact page goes straight to a real inbox.