Developer tools

Format JSON, hash a file or generate an identifier. Processing runs in your tab.

4 tools ready to use

JSON Formatter & ValidatorPretty-print, minify, validate and explore a JSON payload as a collapsible tree. Errors are pinned to a line and a column.Open toolFree · in-browser Hash GeneratorGenerate MD5, SHA-256 and four more checksums. Hash files locally, verify a digest or create HMAC and SRI values.Open toolFree · in-browser UUID GeneratorVersion 4, 7, 1, 5 and nil identifiers, one or ten thousand at a time, from your own browser. Reads a UUID back apart too.Open toolFree · in-browser QR Code GeneratorLinks, Wi-Fi, contacts and more, drawn in your own tab and saved as PNG or SVG. Static codes, so nothing expires.Open toolFree · in-browser

This is the shelf where an upload form is genuinely dangerous. Formatting a JSON payload means pasting whatever was in it: a bearer token, a customer record, an API key. On a hosted formatter that is now on a server you have never heard of, in a log you cannot read.

Here the parsing happens in your tab. Signed-in text drafts and settings save privately, so avoid putting secrets into saved text fields. Google Analytics sends usage events without your input. Turn it off through Analytics settings in the footer.

2 more in build

Named and designed, but not written yet. They are listed so you can see where this shelf is going. No dates, because a promised date on a free project is a broken one waiting to happen.

Base64 Encoder & DecoderText, files and data URIs, both directions, with UTF-8 handled properly.In build

Regex TesterMatch, highlight and explain a pattern against your own sample, with capture groups broken out.In build

Guides for these tools

How to verify a file checksumCheck a download with SHA-256 in your browser, Windows, macOS or Linux. Understand mismatches and what a match proves.How to fix a JSON syntax errorWhat the error message means in JavaScript, Python, PHP and Java, the eight mistakes behind nearly all of them, and how to find the character at fault.UUID versions: v4, v7, v1 and v5 comparedWhich version to reach for, why v7 sorts and v4 does not, what a v1 gives away, and the one line that makes one in SQL, Python, Java, C#, Go and JavaScript.Do QR codes expire?A static code never expires and a dynamic one is a subscription. How to tell which you were given, why free codes stop working, and what to do when one already has.

This is one shelf of the full floi directory. The rest is media, text, developer, documents, education and design.