Free Developer Tools
Browser-based utilities for formatting data, decoding tokens, testing patterns, comparing text, and debugging everyday development tasks.
Popular tools
JSON Formatter Online — Format & Validate JSON Free
Format and validate JSON online for free. Paste messy JSON and get clean, indented output instantly. No signup, runs in your browser.
Base64 Encoder & Decoder Online — Free Tool
Encode text to Base64 or decode Base64 back to text. Free online tool runs entirely in your browser. No upload, no signup. Instant results.
URL Encoder & Decoder Online — Free Percent Encoding
Encode or decode URLs with percent-encoding. Free online tool handles query strings, special characters, and Unicode instantly. No signup required.
HTML Entities Encoder & Decoder Online — Free
Encode special characters to HTML entities or decode them back. Free online tool for web developers. No signup, instant results, runs in browser.
Regex Tester Online — Test Regular Expressions
Test regular expressions online with real-time matching. Free regex tester supports flags, groups, and common patterns. No signup.
Text Diff Checker — Compare Text Online
Compare two texts side by side online for free. See additions and deletions highlighted instantly. No signup, runs in your browser.
Unix Timestamp Converter Online — Free Epoch Converter
Convert Unix timestamps to human-readable dates and vice versa. Free online timestamp converter. Supports seconds and milliseconds. No signup required.
JWT Decoder Online — Decode JSON Web Tokens
Decode JWT headers and payloads online for free. Inspect JSON Web Tokens in your browser, no upload. Instant decoding, no signup.
UUID Generator Online — Generate UUID v4 in Bulk Free
Generate random UUID v4 values online for free. Bulk generation, multiple formats (hyphenated, compact, uppercase). No signup, instant results.
Cron Expression Parser Online — Free Cron Translator
Parse cron expressions into human-readable schedules online for free. See next execution times and field descriptions. No signup, instant parsing.
Number Base Converter — Binary, Hex, Decimal
Convert numbers between binary, octal, decimal, and hexadecimal online for free. Instant conversion, no signup required.
JSON to CSV Converter Online — Free JSON Conversion
Convert JSON arrays to CSV format online for free. Flatten nested structures, choose delimiters, export tabular data. No signup, instant conversion.
Image to Base64 Converter Online — Free Data URI Tool
Convert images to Base64 data URIs online for free. Generate CSS background-image and HTML img src code. No upload, runs in your browser, no signup.
IP Address Lookup — Find Your IP Online
Look up your public IP address and geolocation online for free. See ISP, country, city. No signup, instant results.
CSV Viewer Online — View CSV Data Free
View and analyze CSV data in an interactive table online for free. Sort, filter, search. No signup, runs in your browser.
Binary Translator — Text to Binary Online
Convert text to binary or binary to text online for free. Supports ASCII and UTF-8. Instant translation, no signup required.
Text to Hex Converter Online — Free Hex Encoder
Convert text to hexadecimal and back online for free. Multiple output formats: spaced, prefixed, continuous. Instant conversion, no signup required.
JSON to YAML Converter Online — Free Bidirectional
Convert JSON to YAML and YAML to JSON online for free. Handles nested structures and arrays. Instant conversion, no signup required. For configs.
Markdown to HTML Converter Online — Free MD to HTML
Convert Markdown to clean HTML online for free. Supports GFM, tables, code blocks, links. Instant conversion, no signup required. For blogs and docs.
Screen Resolution Detector — Check Display
Detect your screen resolution, viewport, pixel ratio, and color depth online for free. No signup, instant detection.
PDF Merge & Split Online — Combine or Split PDFs Free
Merge multiple PDFs into one or split a PDF into separate pages. Free online tool runs in your browser. No upload, no signup, fully private.
Image to PDF Converter Online — Free JPG to PDF Tool
Convert JPG, PNG, and WebP images to PDF online for free. Combine multiple images into one PDF. Runs in your browser, no upload, no signup.
Common tasks
FAQ
Do these developer tools upload my data?
Most tools run directly in your browser, which keeps pasted snippets local to your device.
Are these tools free to use?
Yes. FreeToolJet tools are free and do not require signup.