Online Developer Tools
— Fast, Private, Free
In-Browser Developer Tools
A curated collection of browser-based developer tools for formatting, encoding, conversion, PDF workflows, security checks, QR generation, and text cleanup
— practical examples, local processing, and zero sign-up.
Why Choose WebUtils?
Lightning‑Fast
Instant results with browser-based processing for supported tools, plus manual modes for heavier files or text that should be reviewed before each run.
Privacy‑First
Your data stays on your device with no uploads to our servers, which is safer for tokens, payloads, headers, PDFs, and copied documents that should not leave the browser.
Developer‑Friendly
Each tool focuses on a practical workflow with examples, validation feedback, and clear input/output controls so the result can be checked before it is copied elsewhere.
Multi-Window Workflow
Detach tools into separate windows to view input and output simultaneously on different screens with real-time sync.
Popular Developer Tools
Open the most useful browser-based tools for formatting, encoding, PDF workflows, authentication, QR generation, and data conversion.
JSON Formatter and Validator Online | Format, Minify, Debug
Format, validate, minify, and inspect JSON with examples and local processing.
Base64 Encoder and Decoder Online | UTF-8 and URL-Safe Text
Encode or decode Base64 text with UTF-8 support for APIs, JSON, and debugging.
PDF Merge Online | Combine PDF Files Locally with No Upload
Merge multiple PDFs in your browser before submitting or sharing document packages.
Hash Generator Online | MD5, SHA-256 and SHA-512 Checksums
Generate MD5, SHA-1, SHA-256, and SHA-512 digests for checksums and fingerprints.
URL Encoder and Decoder Online | Query String Percent Encoding
Encode and decode URL components, query strings, and UTF-8 percent-encoded text.
JWT Decoder Online | Decode Claims, Header and Expiration
Decode JWT headers and payload claims locally for auth and API debugging.
UUID v4 Generator Online | Bulk GUIDs with Web Crypto
Generate secure UUID v4 identifiers in bulk with case and hyphen options.
QR Code Generator Online | URL, Wi-Fi, vCard, PNG and SVG
Create QR codes for URLs, text, Wi-Fi, and contact data with downloadable output.
CSV to JSON and JSON to CSV Converter Online | Local Data Tool
Convert CSV to JSON or JSON to CSV for spreadsheets, APIs, and data cleanup.
Workflow Guides
Use these focused guides to finish common developer tasks, then open the matching browser tool.
View all guidesFormat JSON for API debugging
Learn how to format, validate, and inspect API JSON responses so missing commas, wrong nesting, and invalid payloads are easier to find.
Read guideDecode a JWT safely before debugging authentication
Learn how to inspect JWT headers and payload claims without treating decoded tokens as verified or sharing secrets by accident.
Read guideBase64 decode an API payload
Learn how to decode Base64 API fields, inspect UTF-8 text safely, and avoid confusing encoding with encryption.
Read guideConvert CSV to JSON for spreadsheet data cleanup
Learn how to convert spreadsheet CSV exports into JSON while checking headers, delimiters, empty cells, and nested-looking values.
Read guideFix CSV and JSON conversion errors
Diagnose CSV to JSON and JSON to CSV conversion problems caused by headers, quoted commas, delimiters, empty cells, encoding, and malformed JSON.
Read guideMerge PDF files privately in the browser
Learn how to combine PDF files in a browser workflow while checking page order, file names, and sensitive document handling.
Read guidePopular Tools
Open focused utilities with examples, local processing, and clear output actions for JSON, PDF, encoding, security, QR, and text cleanup tasks
Base64 Encoder and Decoder Online | UTF-8 and URL-Safe Text
Encode or decode Base64 text with UTF-8 support and local-only processing.
QR Code Generator Online | URL, Wi-Fi, vCard, PNG and SVG
Generate static QR codes for URLs, Wi-Fi, contacts, and text as PNG or SVG.
UUID v4 Generator Online | Bulk GUIDs with Web Crypto
Generate bulk UUID v4 and GUID values locally with format options.
Get Started Free
No install or sign-up. The curated tool set runs locally in your browser for speed, privacy, and repeatable developer workflows.
Browse All Tools