Good engineering starts with a clearer answer.

Calculate with confidence. Understand the result. Practical tools and learning for IT engineers, from your first subnet to everyday infrastructure operations.

Open the toolbox →Learn something new
No signupBrowser-based toolsInputs processed locally

Popular tools

Browse tool categories
Networking

Subnet Calculator

Find the network, address range and subnet mask for an IPv4 address.

Open tool →Developer & Data

JSON Formatter / Validator / Minifier

Validate JSON syntax and show readable or compact output.

Open tool →APIs

API Request Builder

Build a cURL command from a URL, method, headers and body.

Open tool →Infrastructure & Storage

RAID Calculator

Compare usable storage and disk-failure tolerance for common RAID levels.

Open tool →Security & Identity

JWT Decoder

Inspect the header and payload of a compact JSON Web Token.

Open tool →AI Engineering

LLM Cost Calculator

Estimate one request cost from token counts and your supplied prices.

Open tool →

Find your toolbox

01 / TOOLBOX

Networking

Plan address space, compare transfer rates and make network values easier to read.

12 tools →02 / TOOLBOX

Infrastructure & Storage

Size storage and virtual machines, compare RAID layouts and plan backups.

12 tools →03 / TOOLBOX

Reliability & Operations

Turn service targets into practical downtime, recovery and handover plans.

8 tools →04 / TOOLBOX

APIs

Build requests, inspect data contracts and plan predictable HTTP integrations.

18 tools →05 / TOOLBOX

Automation

Design schedules, retries, routing rules and repeatable workflows.

12 tools →06 / TOOLBOX

Developer & Data

Format, convert and compare text and structured data without sending it away.

18 tools →07 / TOOLBOX

Security & Identity

Inspect tokens and certificates, generate random values and check message integrity.

6 tools →08 / TOOLBOX

Email & DNS

Build and inspect mail authentication, transport-security and everyday DNS records without claiming to query live DNS.

22 tools →09 / TOOLBOX

AI Engineering

Plan token budgets, costs, retrieval and controlled AI workflows.

12 tools →

Understand it. Then build it.

Interactive learning

Subnetting, without the guesswork

Change the prefix and see the address space respond.

Architecture advice

Does this task need AI?

Explore the trade-offs before building.

Idea finder

A useful next project

39 curated personal and enterprise ideas.

Tool inputs are processed locally. Hosting and future advertising have separate privacy considerations. Privacy policy · Download offline edition