MyDevTools
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Your inputs and files stay in your browser

Developer tools right in your browser

JSON, Base64, hashes, JWT, regex, images and PDF. Nothing to install; your inputs and files never leave the device.

Browse toolsDesktop
Tools
62
Languages
10
Input/file bytes uploaded
0
Try it hereComputed locally
  • Base64aGVsbG8sIGJyb3dzZXI=
  • URLhello%2C%20browser
  • Hex68 65 6c 6c 6f 2c 20 62 72 6f 77 73 65 72
  • SHA-256c986dedbbb63f73ce7c3c5c66954e257210841ec99960eb803fdb500616ed9c2
UTF-8 bytes: 14

Favorites

Recent

Encoding

9
Base64 Encoder / DecoderEncode text or files to Base64 and decode back: standard or URL-safe alphabet, padding control, 76-char line wrap and image preview. Runs in your browser.
Base32 Encoder / DecoderEncode and decode Base32 with RFC 4648, Crockford or z-base-32 alphabets, padding and letter-case options, for text and files, right in your browser.
Base58 Encoder / DecoderEncode and decode Base58 with the Bitcoin, Flickr or Ripple alphabet for text and files up to 1 MiB. Runs locally in your browser, nothing is uploaded.
Hex Encoder / DecoderConvert text or files to hexadecimal and back. Pick charset and case; decode hex with spaces, colons, dashes or 0x prefixes. Runs in your browser.
Hex ViewerOpen a local file as hex and ASCII/UTF-8, jump to an offset, search for bytes, and chart block entropy.
Archive ExplorerOpen ZIP, TAR, TAR.GZ and Zstandard or Brotli archives in the browser, list their contents, extract selected files safely and create new ZIP or TAR archives.
Compression BenchmarkCompress your own file with gzip, Brotli and Zstandard at the levels you choose and compare size, ratio, speed and memory, all in the browser.
URL Encoder / DecoderPercent-encode and decode URLs and query strings in component, URI or form mode, with UTF-8, UTF-16 or Latin-1 charsets. Runs locally in your browser.
HTML Entity Encoder / DecoderEscape HTML special characters as named, decimal or hex entities and decode entities back to text. Handles emoji correctly. Runs entirely in your browser.

Structured Data

13
JSON BeautifierFormat, minify and validate JSON in your browser: 2/4-space or tab indent, recursive key sorting, exact big numbers, open and save .json files.
JSON to TypeScript ConverterGenerate TypeScript interfaces or type aliases from a JSON sample: nested types, merged array items, optional fields, export keyword. Runs in your browser.
Large JSON / JSONL ExplorerOpen, index, search and export large JSON and JSONL files locally with a virtual table, lazy tree and exact numeric values.
Large CSV/TSV ExplorerOpen, filter, sort, group, inspect and export very large CSV or TSV files locally — with column types and CSV, JSONL or Parquet export.
Large Log AnalyzerStream, filter, chart and export very large Serilog, .NET, Nginx, JSON Lines and text logs locally.
Parquet ExplorerOpen a local Parquet file, inspect its schema and row groups, filter rows, group and summarize, and browse selected columns in a virtualized table.
Local Data PlaygroundImport local CSV, JSON, JSONL or Parquet files and query them with DuckDB SQL entirely in your browser.
SQLite ExplorerOpen a local SQLite database in your browser: browse tables, views and indexes, run SQL and export results without uploading the file.
Data Format ConverterConvert local CSV, JSON, JSONL and Parquet files, choose column types and preview the result without uploading your data.
XML BeautifierPretty-print or minify XML in your browser with 2/4-space or tab indent; keeps comments, CDATA and processing instructions and reports parse errors.
YAML Beautifier/ValidatorValidate YAML and reformat it into clean block style with 2-space indentation; errors show line and column. Runs locally via WebAssembly.
Cron Expression GeneratorBuild a cron expression field by field — minute, hour, day, month, weekday — with validation, a plain-language description and the next 5 run times.
Cron Expression ParserExplain a cron expression in plain language, validate every field and list the next 5 run times in your local time zone. Presets and @macros included.

Text Tools

4
Word / Character CounterCount words, characters, lines, paragraphs and sentences as you type, with reading and speaking time. Emoji and Chinese/Japanese text are counted correctly.
Text Case ConverterConvert text to camelCase, snake_case, kebab-case, Title Case, Sentence case, UPPER or lower case. Splits identifiers like XMLHttpRequest correctly.
Text Diff ViewerCompare two texts or files line by line: added, removed and changed lines shown side by side or as a unified diff, with word-level highlights.
Large File DiffCompare two large local files line by line or byte by byte, with whitespace, line-ending and encoding options and a downloadable report.

Why Choose MyDevTools?

MyDevTools is a free collection of browser-based developer utilities: formatters and validators for JSON, XML and YAML, Base64, Hex and URL encoders, hash and HMAC calculators, JWT and X.509 tools, a regex tester, image and PDF utilities, and generators for UUIDs, passwords and QR codes. There is nothing to install and no account to create. For large local files there are explorers for multi-gigabyte CSV, JSON, log, Parquet and SQLite files, a large file diff and an archive explorer, and an optional Windows companion adds an HTTP client and network tools: DNS, WHOIS, TLS, traceroute and port scanning.

Privacy comes from the architecture: the site is a set of static pages, and every tool processes your input inside the browser. Compute-heavy tools such as hashing, encryption, image, PDF and QR processing run in WebAssembly modules compiled from Rust; lighter ones, like the JSON formatter or the text diff, are plain JavaScript. The passwords, keys and files you work with are never uploaded.

  • Privacy First

    Your input and files are processed in the browser and are never sent. If analytics is enabled, it sends only anonymous operation counts, a coarse successful-duration bucket, a failure category, and any fixed-choice vote you submit—never your input.

  • WebAssembly Where It Matters

    Hashing, encryption, image and PDF processing run in Rust-compiled WebAssembly; simpler tools are lightweight JavaScript.

  • Works Offline

    Once a page has been opened, it keeps working without a connection. Install the PWA for quick access.

  • Multilingual

    The interface and tool guides are available in 10 languages.

  • Completely Free

    All tools are free. No hidden payments or subscriptions.

  • Your Own Toolset

    Star the tools you use most. Favorites and recently used tools are kept in your browser.