Free tools for developers & engineers

Popular tools

• UUID Generator

  Generate UUID v1, v4, v5 and v7, singly or in bulk.f47ac10b-58cc-4372

• Binary Converter

  Convert binary to decimal, hexadecimal, octal and ASCII.0x1F4 = 500

• Ohm's Law Calculator

  Solve for voltage, current, resistance or power given any two values.3.3 V / 220 Ω = 15 mA

• Base64 Encoder

  Encode text or file content to Base64.aGVsbG8=

• SHA Hash Generator

  Generate SHA-1, SHA-256, SHA-384 and SHA-512 hashes.2cf24dba… (sha-256)

• Resistor Colour Code Decoder

  Decode 4, 5 and 6-band resistor colour codes to resistance values.brown black red = 1 kΩ

• Timestamp Converter

  Convert Unix timestamps to human-readable dates and back.1767225600 = 2026-01-01

• JSON Formatter & Validator

  Validate, format and minify JSON, with syntax error highlighting.{ "ok": true }

Browse by category

• String ToolsCase conversion, encoding, find & replace, word counting and text generation.9 tools
• Number ConversionConvert between binary, octal, decimal, hexadecimal and ASCII.7 tools
• CryptographyHash generators, key pair generation, encryption and password utilities.7 tools
• GeneratorsUUID, QR codes, colour codes, timestamps and CRON expressions.5 tools
• Web & DevJSON formatter, JWT decoder, regex tester and HTML entity tools.6 tools
• ElectronicsOhm's law, voltage dividers, resistor codes, LED and PCB calculators.12 tools

How every tool works

1. 1

   Find the tool

   Search or browse. Each tool has its own page and address.

2. 2

   Type or paste

   Results appear live. Mistakes are explained next to the field.

3. 3

   Copy the result

   One click per value. Processing stays on your device.

Why DevGizmo?

• No sign-up required

  Every tool runs in your browser. No account and no form to fill in.

• Built for developers

  Dark by default, usable from the keyboard, and every tool has its own address you can bookmark.

• Electronics included

  Ohm's law, voltage dividers, resistor codes and PCB calculators sit next to the developer tools.

• Always free

  Ads pay for the site. The tools stay free, with no paywall.