16 tools — 0 signup required

Diagnostics for the network you're building.

Free, instant, browser-only tools for developers and network engineers. Nothing you type is sent to a server unless a tool explicitly says otherwise — every calculation runs locally.

Patch panel — network & IP

PORT 01

Subnet Calculator

CIDR to netmask, host range, broadcast address and usable host count.

PORT 06

DNS Lookup

Query A, AAAA, MX, TXT and NS records for any domain.

PORT 13

My IP & Geolocation

See your public IP address, ISP, and approximate location.

PORT 14

MAC Address Vendor Lookup

Identify the hardware manufacturer behind any MAC address.

PORT 15

ASN / BGP Lookup

Find the autonomous system and network operator behind an IP.

PORT 16

WHOIS Domain Lookup

Registration, registrar and expiry details for any domain.

Patch panel — dev & security

PORT 02

JWT Decoder

Inspect header and payload claims of any JSON Web Token.

PORT 03

Base64 Encode / Decode

Convert text and Base64 strings both directions, UTF-8 safe.

PORT 04

JSON Formatter

Validate, pretty-print, or minify JSON with clear error location.

PORT 05

Regex Tester

Test a pattern against sample text with live match highlighting.

PORT 07

Password Strength & Breach Check

Local strength scoring plus an anonymous breach lookup.

PORT 17

HTTP Security Headers Analyzer

Check any site's security headers with fix recommendations.

PORT 18

SSL Certificate Checker

Inspect a domain's TLS certificate, issuer and expiry date.

PORT 08

Hash Generator

SHA-1, SHA-256, SHA-384 and SHA-512 digests of any text.

Patch panel — utility

PORT 09

UUID Generator

Generate one or a batch of RFC 4122 v4 UUIDs.

PORT 10

URL Encoder / Decoder

Percent-encode or decode query strings and full URLs.

PORT 11

Unix Timestamp Converter

Convert between Unix time and human-readable dates, both ways.

PORT 19

Website Response Time Checker

Measure how fast a website responds right now.

PORT 12

Color Converter

Convert HEX, RGB and HSL with a live preview.

Why ChistStudio

Nothing leaves your browser, by default

Subnet math, JWT decoding, JSON parsing, Base64, regex, hashing and UUIDs all run in local JavaScript. Tools that need external data (DNS, WHOIS, IP lookups) only send the minimum required — never your password or personal data.

Built by a working security engineer

ChistStudio is built and maintained by a security and network engineer who uses these exact tools day to day — not a generic template.