Tools for developers to test, format, and optimize code.
A simple client to test REST API endpoints.
Calculate file permissions for chmod.
Check color contrast for WCAG accessibility.
Make your messy CSS readable in seconds.
Visually create and customize CSS gradients.
Compress CSS code to reduce file size.
Make your messy HTML readable in seconds.
Convert special characters to HTML entities.
Compress HTML code to reduce file size.
Clean up messy JavaScript and JSON code effortlessly.
Pretty-print and validate JSON.
These are the utilities most developers end up Googling individually — a JSON formatter, a CSS minifier, a chmod calculator — collected in one place that loads instantly. Every tool runs in your browser, so no code or credentials leave your machine.
The collection covers the tasks that come up across every stack: front-end formatting and compression, accessibility checks, permission calculation, and API testing. Each tool does one job and has a clean interface so you can get in, do the thing, and get back to your editor.
Yes. The JSON Formatter highlights syntax errors and tells you where the problem is before formatting. If your JSON is invalid, the tool shows an error rather than silently producing malformed output.
All formatting, minification, and beautification tools run entirely in your browser using JavaScript — nothing is sent to a server. For the API Fetch Tester, your request goes directly from your browser to the endpoint you specify; it does not pass through ToolsVenue servers.
It tests foreground/background color pairs against the WCAG 2.1 AA and AAA contrast ratio thresholds (4.5:1 and 7:1 for normal text, 3:1 and 4.5:1 for large text). The result tells you whether each combination passes or fails each level.
Enter the permission bits you want for Owner, Group, and Others (read, write, execute) in the Chmod Calculator. The tool outputs the numeric octal value (e.g., 755 or 644) and the symbolic notation you can use in a terminal command.
Looking for something else? Browse Image & Media Tools or see all categories.
← All categoriesOver 40 browser-based utilities — no signup, no upsell, nothing to install.