Developer Tools

Fast, private browser-based tools for formatting, decoding, encoding, hashing, network planning, and schedule debugging.

AI Tool Alternatives

Independent comparisons after AI tool pricing changes — no affiliate links.

Runs locally where possible

1. Format and validate data

JSON Formatter

Format, minify, and validate JSON locally in your browser — no data leaves your machine.

Format JSON now

URL Encoder

Encode and decode URL components and query strings for safe transport.

Encode or decode

Base64

Encode and decode Base64 strings for data transport and embedding.

Convert Base64

2. Inspect tokens and timestamps

JWT Decoder

Decode header and payload locally, inspect exp / iat / nbf, and remember decode does not verify trust.

Inspect token claims

Timestamp Converter

Convert between Unix timestamps and human-readable dates across time zones.

Convert timestamp

3. Network planning

CIDR Calculator

Calculate IP ranges, subnet masks, broadcast addresses, and host counts for network planning.

Plan subnets

HTTP Status Codes

Quick reference for HTTP status codes with descriptions and common usage patterns.

Look up codes

4. Scheduling

Cron Expression Parser

Parse, validate, and preview cron schedules with next-run dates and human-readable descriptions.

Parse cron

5. Hashing and number formats

Hash Generator

Generate MD5, SHA-1, SHA-256 hashes locally for data integrity checks and verification.

Generate hash

Hex Converter

Convert between hexadecimal, decimal, and other formats for low-level debugging.

Convert hex

Number Base Converter

Convert numbers between binary, octal, decimal, hexadecimal, and custom bases.

Convert numbers

Disk Partition Calculator

Calculate optimal disk partition sizes and align boundaries for storage planning.

Plan partitions

6. AI and local LLMs

LLM Fit Calculator

Check which open-source LLMs fit your GPU, Mac, or CPU — memory fit and speed estimates for 30 popular models.

Check my hardware

Tutorials

How to debug a JWT safely How to read a cron expression JSON formatting vs validation

Your Privacy is Protected

All calculations are performed locally in your browser. We do not store or transmit your data.