16 free browser tools · no account
Free browser tools for JSON, data, text, URLs, and developer tasks
Format, convert, query, validate, and compare structured data; inspect JWT claims and URL parameters; test text, regex, cron, timestamps, encodings, hashes, and dimensions. Every tool runs in your browser, and input is not intentionally uploaded.
Text tools
Compare, measure, and inspect writing or plain text without uploading it.
Text Diff Checker
Compare two text blocks line by line and highlight additions, removals, and unchanged lines. Your text stays in your browser.
Open tool →TextWord Counter
Count words, characters, sentences, paragraphs, and estimated reading time locally. Analyze English or multilingual text without upload.
Open tool →JSON & data tools
Format, convert, query, validate, and compare structured data in one local workflow.
JSON Formatter & Validator
Format, validate, or minify JSON locally. Find syntax errors by line, column, and offset; inspect structure and size; copy or download the result.
Open tool →DataYAML to JSON & JSON to YAML Converter
Convert YAML 1.2 to formatted JSON or JSON back to YAML in your browser. Supports bounded multi-document input without uploading configuration.
Open tool →DataJSON Schema Validator
Validate JSON data against Draft 2020-12 or Draft 7 locally. Get instance paths, schema paths, and bounded errors without remote references.
Open tool →DataJSONPath Tester
Run a JSONPath-Plus expression against JSON locally and inspect matched values and concrete JSON Pointer paths. Safe evaluation and bounded output.
Open tool →DataJSON Diff & Compare
Compare two JSON values by JSON Pointer path, ignore object key order, and choose ordered or unordered arrays. Runs locally with bounded output.
Open tool →Developer tools
Debug expressions, URLs, tokens, schedules, encodings, timestamps, and hashes.
JavaScript Regex Tester
Test a JavaScript regular expression, flags, match positions, and capture groups locally in your browser with no text upload.
Open tool →DeveloperCron Expression Validator
Validate and explain a classic five-field Unix cron expression. See field errors and scheduler caveats instantly in your browser.
Open tool →DeveloperURL Encoder & Decoder
Encode text as a URL component or decode percent-encoded text locally. Handle spaces, Unicode, query values, and reserved characters.
Open tool →DeveloperBase64 Encoder & Decoder
Encode UTF-8 text to Base64 or decode Base64 back to Unicode text locally in your browser. No payload upload or account required.
Open tool →DeveloperUnix Timestamp Converter
Convert Unix seconds, Unix milliseconds, or an ISO date to UTC, ISO 8601, and your local browser time instantly and privately.
Open tool →DeveloperSHA-256 Hash Generator
Generate a lowercase SHA-256 hexadecimal digest from UTF-8 text using the browser Web Crypto API. Input stays on your device.
Open tool →DeveloperJWT Decoder & Expiration Checker
Decode a JWT header and payload, then inspect exp, nbf, iat, issuer, and audience locally. No signing secret, upload, or account required.
Open tool →DeveloperQuery String Parser & Editor
Parse a URL query string into editable ordered rows, preserve repeated keys and blanks, then rebuild it locally with clear encoding behavior.
Open tool →Design tools
Calculate practical dimensions for visual assets without selecting or uploading a file.
Reproduce a failure before you debug it
Versioned synthetic fixtures create a stable input that docs, tests, issue reports, and tutorials can cite without exposing production data.
Follow one JSON task from input to verified output
The guide explains which local utility to use for formatting, schema checks, JSONPath queries, diffs, and reproducible parser failures.
Drei lokale Werkzeuge für deutschsprachige Suchanfragen
Diese kleine Sprachversion testet echte Nutzung mit eigener Übersetzung und denselben lokalen Funktionen.
JSON formatieren und validieren
JSON formatieren, minimieren und validieren – kostenlos im Browser, ohne Upload und ohne Konto.
Werkzeug öffnen →Deutsch · PilotJSON Schema auf Deutsch prüfen
JSON-Instanzen gegen JSON Schema Draft 2020-12 oder Draft 7 prüfen – lokal im Browser und ohne Upload.
Werkzeug öffnen →Deutsch · PilotYAML ↔ JSON Konverter
YAML und JSON im Browser umwandeln, ohne Upload. Kommentare, Anker und Zielsystem-Grenzen transparent prüfen.
Werkzeug öffnen →Need to clean, validate, split, or compare CSV files?
Use the focused CSV Local Tools workflow for browser-local CSV cleaning, duplicate SKU checks, catalog diffs, encoding repair, column mapping, validation, and WooCommerce import preflight.
Useful before an account, upload, or sales call
These utilities are deliberately narrow. Each page performs one real action, includes a worked example, states its limits, and works without uploading the input. The collection tests whether useful task completion can earn recurring organic discovery.
Traffic, indexing, tool runs, repeated use, and revenue are measured separately. A published page or search impression is not treated as proof of a sustainable business.