FastDevTools
Library

All 30 tools

Search by name, filter by category, switch the layout — every tool runs locally in your browser.

30 / 30 shown
JSON Tools

JSON Formatter

Pretty-print and indent JSON instantly.

/json-formatter Open
JSON Tools

JSON Minifier

Strip whitespace to compress JSON.

/json-minifier Open
JSON Tools

JSON Validator

Check if JSON is syntactically valid.

/json-validator Open
JSON Tools

JSON to CSV

Convert a JSON array of objects into CSV.

/json-to-csv Open
JSON Tools

JSON to XML

Translate JSON into well-formed XML.

/json-to-xml Open
JSON Tools

JSON to YAML

Convert JSON into readable YAML.

/json-to-yaml Open
Encoding & Security

Base64 Encode/Decode

Encode or decode Base64 text.

/base64 Open
Encoding & Security

URL Encode/Decode

Percent-encode or decode URLs.

/url-encode-decode Open
Encoding & Security

JWT Decoder

Decode JWT header and payload (no signature verification).

/jwt-decoder Open
Encoding & Security

Hash Generator

Generate MD5, SHA-1, SHA-256, SHA-512 hashes.

/hash-generator Open
Encoding & Security

Password Generator

Create strong random passwords.

/password-generator Open
Encoding & Security

HMAC Generator

Compute HMAC with SHA-256/384/512.

/hmac-generator Open
API & Network

API Request Tester

Send HTTP requests from your browser.

/api-request-tester Open
API & Network

HTTP Headers Checker

Inspect response headers of any URL.

/http-headers-checker Open
API & Network

IP Finder

Look up your public IP and basic info.

/ip-finder Open
API & Network

User-Agent Parser

Parse a UA string into browser/OS/device.

/user-agent-parser Open
API & Network

DNS Lookup

Resolve A, AAAA, MX, TXT records via DoH.

/dns-lookup Open
API & Network

cURL Converter

Convert a cURL command to fetch() code.

/curl-converter Open
Code Tools

HTML Beautifier

Format and indent HTML markup.

/html-beautifier Open
Code Tools

CSS Minifier

Remove whitespace and comments from CSS.

/css-minifier Open
Code Tools

JS Minifier

Compact JavaScript by removing whitespace.

/js-minifier Open
Code Tools

Code Diff

Compare two text blobs line-by-line.

/code-diff Open
Code Tools

Regex Tester

Test regular expressions against sample text.

/regex-tester Open
Code Tools

Text Case Converter

Convert text between case styles.

/text-case-converter Open
Utility Tools

Timestamp Converter

Convert between Unix timestamps and dates.

/timestamp-converter Open
Utility Tools

UUID Generator

Generate v4 UUIDs.

/uuid-generator Open
Utility Tools

Color Converter

Convert between HEX, RGB, and HSL.

/color-converter Open
Utility Tools

Lorem Ipsum Generator

Generate placeholder text by paragraphs/words.

/lorem-generator Open
Utility Tools

Random Number

Pick random integers in any range.

/random-number Open
Utility Tools

Word Counter

Count words, characters, sentences, lines.

/word-counter Open
JSON Formatter JSON Tools

Pretty-print and indent JSON instantly.

JSON Minifier JSON Tools

Strip whitespace to compress JSON.

JSON Validator JSON Tools

Check if JSON is syntactically valid.

JSON to CSV JSON Tools

Convert a JSON array of objects into CSV.

JSON to XML JSON Tools

Translate JSON into well-formed XML.

JSON to YAML JSON Tools

Convert JSON into readable YAML.

Base64 Encode/Decode Encoding & Security

Encode or decode Base64 text.

URL Encode/Decode Encoding & Security

Percent-encode or decode URLs.

JWT Decoder Encoding & Security

Decode JWT header and payload (no signature verification).

Hash Generator Encoding & Security

Generate MD5, SHA-1, SHA-256, SHA-512 hashes.

Password Generator Encoding & Security

Create strong random passwords.

HMAC Generator Encoding & Security

Compute HMAC with SHA-256/384/512.

API Request Tester API & Network

Send HTTP requests from your browser.

HTTP Headers Checker API & Network

Inspect response headers of any URL.

IP Finder API & Network

Look up your public IP and basic info.

User-Agent Parser API & Network

Parse a UA string into browser/OS/device.

DNS Lookup API & Network

Resolve A, AAAA, MX, TXT records via DoH.

cURL Converter API & Network

Convert a cURL command to fetch() code.

HTML Beautifier Code Tools

Format and indent HTML markup.

CSS Minifier Code Tools

Remove whitespace and comments from CSS.

JS Minifier Code Tools

Compact JavaScript by removing whitespace.

Code Diff Code Tools

Compare two text blobs line-by-line.

Regex Tester Code Tools

Test regular expressions against sample text.

Text Case Converter Code Tools

Convert text between case styles.

Timestamp Converter Utility Tools

Convert between Unix timestamps and dates.

UUID Generator Utility Tools

Generate v4 UUIDs.

Color Converter Utility Tools

Convert between HEX, RGB, and HSL.

Lorem Ipsum Generator Utility Tools

Generate placeholder text by paragraphs/words.

Random Number Utility Tools

Pick random integers in any range.

Word Counter Utility Tools

Count words, characters, sentences, lines.