Developer tools that stay in your browser.

Format JSON, decode JWTs, generate UUIDs, test regex, convert timestamps and solve the small things you hit a dozen times a day. Paste, process, copy — 49 tools, no signup, nothing uploaded.

100% client-sideNo signupNo uploadsFast & private

Encoding

JWT Decoder

Decode a JWT, check expiry and verify its signature

Runs locally
Open

JWT Encoder

Create and sign a JWT locally

Runs locally
Open

Base64

Encode and decode Base64 and Base64URL, text or files

Runs locally
Open

URL Encode / Decode

Percent-encode URLs and query values

Runs locally
Open

Hash Generator

SHA-256, MD5, SHA-512 and HMAC of text or files

Runs locally
Open

Bcrypt Generator

Hash passwords with bcrypt and verify them against a hash

Runs locally
Open

URL Parser

Split a URL into parts and edit its query string

Runs locally
Open

HTML Entities

Encode and decode HTML entities like & and é

Runs locally
Open

Formatters

JSON Formatter

Beautify, minify and sort JSON, with a tree and search

Runs locally
Open

XML Formatter

Pretty-print and check XML, with XPath and a tree

Runs locally
Open

YAML Formatter

Format, tidy, strip comments & validate YAML

Runs locally
Open

SQL Formatter

Pretty-print & minify SQL across dialects

Runs locally
Open

Data

JSON to CSV

Flatten a JSON array into CSV for Excel or Sheets

Runs locally
Open

CSV to JSON

CSV or TSV to JSON records with types detected

Runs locally
Open

JSON to YAML

JSON to YAML for Kubernetes, Compose and CI

Runs locally
Open

YAML to JSON

YAML to JSON with anchors and multi-document files

Runs locally
Open

JSON → Code

Generate typed models from a JSON payload

Runs locally
Open

Properties Viewer

Read, clean, list keys and convert .properties files

Runs locally
Open

Properties Compare

Diff two .properties files by key and value

Runs locally
Open

Properties to YAML

Spring application.properties to application.yml

Runs locally
Open

YAML to Properties

Spring application.yml to .properties

Runs locally
Open

JSON Toolkit

JSON Validator

Validate, format & explore JSON in a live tree view

Runs locally
Open

JSON Sort Keys

Alphabetise keys at every level

Runs locally
Open

JSON Flattener

Collapse nesting into dot-notation keys

Runs locally
Open

JSON Unflattener

Rebuild nesting from dot-notation keys

Runs locally
Open

JSON Escape

Escape or unescape a JSON string literal

Runs locally
Open

Remove Nulls

Strip every null value

Runs locally
Open

Remove Empty Values

Strip nulls, "", [] and {}

Runs locally
Open

JSON Merge

Deep-merge two documents

Runs locally
Open

JSON Tree Viewer

Explore a payload as a collapsible tree

Runs locally
Open

JSON Statistics

Node counts, depth and type breakdown

Runs locally
Open

JSONPath Evaluator

Query with $.path expressions

Runs locally
Open

JSON Schema Generator

Infer a schema from a sample payload

Runs locally
Open

Text

Diff Checker

Compare two blocks of text

Runs locally
Open

Color & CSS Units

HEX, RGB, HSL and px / rem / em / pt

Runs locally
Open

Case Converter

camelCase, snake_case, kebab-case and more

Runs locally
Open

Regex Tester

Test JavaScript regex with highlighting, groups and replace

Runs locally
Open

Number Base Converter

Binary, octal, decimal and hex with two’s complement

Runs locally
Open

Markdown Preview

Live GitHub-flavoured Markdown with Mermaid diagrams

Runs locally
Open

Time

Unix Timestamp

Epoch to date and back in any time zone

Runs locally
Open

Cron Builder

Decode cron expressions & preview next runs

Runs locally
Open

Generators

Mock Data

Generate fake records as JSON, CSV or SQL

Runs locally
Open

UUID Generator

Bulk UUID v4 and v7, ULID and Nano ID

Runs locally
Open

UUID v7 Generator

Time-ordered UUIDs with the bit layout explained

Runs locally
Open

Password Generator

Cryptographically random passwords

Runs locally
Open

Lorem Ipsum

Placeholder copy by word, sentence or paragraph

Runs locally
Open

Reference

SQL Query Guide

Searchable SQL syntax, recipes and gotchas

Open

Docker & Swarm Guide

Searchable Docker and Swarm commands with examples

Open

HTTP Reference

Status codes, methods & headers

Open

Found a bug or missing a tool?

Tell us in a short form — no email app needed. It is the only thing on DevPocket that sends what you type, and only when you press Send.

About DevPocket

How it works in 3 steps · 4 common use cases · 4 questions answered

How it works

  1. 1.Pick a tool from the menu, the search box (Cmd/Ctrl-K) or the grid on this page.
  2. 2.Paste your input. Every tool processes it as you type — there is no Run button and no upload step.
  3. 3.Copy the result, or export it as a file. Nothing you paste is sent to a server at any point.

Common use cases

  • •Reading a minified API response during a production incident
  • •Checking what is inside a JWT without pasting it into a site that logs it
  • •Generating seed data, UUIDs or passwords while writing a migration
  • •Working out what a cron expression will actually do before shipping it

FAQ

Is anything I paste uploaded?

No. Every tool runs in JavaScript in your own tab. You can confirm it by opening DevTools, switching to the Network tab and using any tool — after the initial page load there are no further requests.

Does it work offline?

Yes. After your first visit a service worker keeps a copy of every tool’s code in your browser, so DevPocket opens and works with no connection at all. You can also install it as an app from your browser’s address bar. The cache holds the site’s own files only, never anything you type.

Is there a sign-up, a paid tier or a usage limit?

None of the three. There is no account system, no payment, and no server to rate-limit you.

Is my data stored in the browser?

Only your theme choice, favourites, recently used tools and split-pane widths, in localStorage. Tool inputs are never persisted — reloading the page clears them.