Developer Tools.
8 free browser-based utilities built for daily development work — no install, no upload, no account.
Developer tools should be instant. When you need a UUID, a Base64 string, or a diff between two JSON payloads, you shouldn't be searching for an app to install or a tool that buries the feature behind an account form. The developer tools on Powertoys.Online load in your browser and return results immediately — processing everything client-side so your data never leaves your machine.
The GUID Generator produces RFC 4122-compliant UUIDs in version 1 (time-based) and version 4 (random) formats. Generate single values for copy-paste use or produce batches for test fixtures, seed data, and database migration scripts. UUIDs are generated using the browser's built-in Web Crypto API — not a server-side call.
The Base64 encoder and decoder handles bidirectional conversion between plain text and Base64 strings, including URL-safe Base64 variants. Base64 encoding appears throughout web development — encoding binary data for email transport, wrapping JWT payloads, and encoding credentials for HTTP Basic Authentication headers.
For data quality work, the JSON Data Compare tool diffs two JSON documents side by side and highlights every field that has changed, been added, or been removed. Useful for comparing API responses across environments and hunting the specific field that changed between a working and broken response. The JSON Schema Compare does the same for schema definitions — essential when reviewing API contract changes between versions.
The ASCII Table provides a full reference for all 128 standard ASCII characters with decimal, hexadecimal, binary, and character representations in a single searchable table. The Number Base Converter converts between binary, octal, decimal, and hexadecimal — enter a value in any base and see all four representations update simultaneously.
The Fixed Length Viewer parses positional flat files used in legacy enterprise systems — EDI transactions, banking file formats, and mainframe outputs. Define column widths, name your fields, and the viewer renders each record as a clean labeled row.
All Developer Tools
8 tools — all free, all run in your browser.
Frequently Asked Questions
- What is the difference between a UUID and a GUID?
- UUID (Universally Unique Identifier) and GUID (Globally Unique Identifier) refer to the same thing — a 128-bit identifier formatted as
xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx. GUID is Microsoft's term for the same standard. Both follow RFC 4122. - Is Base64 a form of encryption?
- No. Base64 is an encoding scheme, not encryption. It converts binary data into a text-safe ASCII string using 64 printable characters. Anyone with the Base64 string can decode it instantly — no key required. For actual security, use encryption rather than Base64 encoding.
- Does the JSON Compare tool upload my data to a server?
- No. All JSON processing happens entirely in your browser using JavaScript. Your JSON documents are never transmitted anywhere. This makes it safe to use with API responses that contain sensitive application data.
- What number bases does the base converter support?
- The Number Base Converter supports binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16) — the four bases most commonly used in software development, systems programming, and hardware work.
- What file formats does the Fixed Length Viewer support?
- The Fixed Length Viewer works with any plain-text positional file — .txt, .dat, .edi, and similar formats used in EDI, banking, and mainframe data exchange. You define the field layout yourself by specifying column widths and names.