12 tools · client-side · keyboard first

Paste. Transform. Done.

Fast developer utilities that run entirely in your browser. No signup and no uploads: every tool is one fast page, and every one is two keystrokes away.

No uploads
No accounts
Works offline after one visit

Paste anythingwe will pick the tool

// all tools

// one payload

One payload, four tools, zero round trips.

Scroll to send an illustrative API response through the formatter, the JWT decoder and the timestamp converter. The outputs are computed live in this tab by the same code the tool pages run, and timed.

01 / raw.json

Minified JSON

What the API gave you: one line, a token buried inside.

// 1 line, 202 bytes, as the API sent it
{"user":"ada","role":"admin","token":"eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJhZGEiLCJyb2xlIjoiYWRtaW4iLCJpYXQiOjE3NjEwMDAwMDAsImV4cCI6MTc2MTAwMzYwMH0.aWxsdXN0cmF0aXZlLXNpZ25hdHVyZQ","ttl":3600}

02 / format

Format it

Indented and colored, keys kept in the order they arrived, with a count of what is inside.

open json-formatter →

{
  "user": "ada",
  "role": "admin",
  "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJhZGEiLCJyb2xlIjoiYWRtaW4iLCJpYXQiOjE3NjEwMDAwMDAsImV4cCI6MTc2MTAwMzYwMH0.aWxsdXN0cmF0aXZlLXNpZ25hdHVyZQ",
  "ttl": 3600
}
// 1 object, 3 strings, 1 numbers, depth 1

03 / jwt

Decode the token

The JWT split into header and claims. The signature is never checked or sent anywhere.

open jwt-decoder →

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJhZGEiLCJyb2xlIjoiYWRtaW4iLCJpYXQiOjE3NjEwMDAwMDAsImV4cCI6MTc2MTAwMzYwMH0.aWxsdXN0cmF0aXZlLXNpZ25hdHVyZQ

// header
{
  "alg": "HS256",
  "typ": "JWT"
}
// claims
{
  "sub": "ada",
  "role": "admin",
  "iat": 1761000000,
  "exp": 1761003600
}
// status: expired (signature not checked)

04 / time

Read the timestamps

iat and exp converted to UTC, your local time and how long ago, then checked against the ttl field.

open timestamp-converter →

// iat 1761000000 (seconds, auto-detected)
utc      2025-10-20T22:40:00.000Z
relative 1 year ago

// exp 1761003600 (seconds, auto-detected)
utc      2025-10-20T23:40:00.000Z
relative 1 year ago

// exp - iat = 3600 s  ✓ matches "ttl": 3600

// privacy

Your input stays in this tab.

Developer inputs often contain tokens, customer records and internal configuration. Every tool here runs in your browser, so none of it is sent to a server. Read how that works.

The scan on the right is computed when the site is built. The test suite fails the build if any count is not zero.

$ grep -cE "fetch|XMLHttpRequest|sendBeacon|WebSocket" assets/*.js
assets/json-formatter.js:0
assets/jwt-decoder.js:0
assets/cron-explainer.js:0
assets/regex-tester.js:0
assets/base64.js:0
assets/url-encoder.js:0
assets/uuid-generator.js:0
assets/timestamp-converter.js:0
assets/yaml-json.js:0
assets/text-diff.js:0
assets/cidr-calculator.js:0
assets/color-converter.js:0

// keyboard

Built for the keyboard.

Every action has a key. Press ? on any page for the full list.

Open the command paletteCtrlK
Open the palette (outside a text field)/
Show these shortcuts?
Toggle light and dark themet
Go homegh
Go to all toolsgt
Run the main actionCtrl↵
Copy the outputc
Load the next samples
Focus the inputi
Leave a text fieldEsc
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