Yes. All processing happens in your browser using JavaScript. Your input data — text, files, credentials, anything — is never transmitted to any server. We have no access to what you enter into the tools.

Do I need to create an account?

No. Every tool on the site is fully accessible without registration, login, or providing any personal information. Just open the page and start using the tool.

Are the tools accurate?

Yes, to the best of our ability. Tools use established browser APIs and well-tested open-source libraries where correctness is critical. For security-sensitive contexts (cryptographic hashes, JWT verification, encoding for production systems), always verify results independently.

Does DevConverter work offline?

After the initial page load, most tools continue to work without an internet connection because all logic runs in the browser. Some tools that render output to a canvas or use newer browser APIs may require a fresh load.

How many tools are available?

Currently over 60 tools across 10 categories: encoding and decoding, format conversion, string utilities, hash and security, number bases, date and time, color, generators, network utilities, and image tools. New tools are added regularly.

Can I suggest a new tool?

Yes. Send a brief description of what the tool should do and an example of the input and output to devconverter@proton.me. Tool requests that solve a common developer problem and can run entirely in the browser are most likely to be added.

Developer Tools, All in One Place

A free collection of 60+ browser-based utilities for developers — JSON formatters, Base64 encoders, hash generators, timestamp converters, regex testers, and more. Everything runs locally in your browser. No data is ever sent to a server.

Runs entirely in your browser

Every tool processes data locally using JavaScript. Nothing you type, paste, or upload is ever sent to a server. This is especially important for sensitive inputs like JWTs, private keys, API credentials, and personal data.

No sign-up, no limits

All 60+ tools are immediately available without creating an account, providing an email, or hitting a usage cap. Open a tool, use it, and close the tab. No friction, no dark patterns.

Real-time output

Results update as you type. There is no Submit button to press and no loading spinner to wait for. Instant feedback makes it easy to iterate on your input and understand the output.

Always free

DevConverter is supported by unobtrusive advertising and will remain free to use. No premium tier, no feature paywalls, no conversion limits. The tools that are here today will stay here.

Encoding / Decoding

Base64 Encode / Decode

Encode text to Base64 or decode Base64 back to plain text.

URL Encode / Decode

Percent-encode a URL or decode an encoded URL string.

URL Query Parser

Parse a query string into key-value pairs and rebuild the URL.

Unicode Escape Converter

Convert text to Unicode escape sequences (\uAC00) and back. Supports \uXXXX and \u{X} syntax.

HTML Entity Encode / Decode

Encode special characters as HTML entities (& < >) and decode them back.

Base32 Encode / Decode

Encode and decode data with RFC 4648 Base32 — used in OTP secrets, DNS, and more.

Base58 Encode / Decode

Encode and decode data with Base58 — the alphabet used by Bitcoin addresses, IPFS CIDs, and other blockchain identifiers.

JWT Decoder

Decode and inspect JWT (JSON Web Token) headers and payloads. Displays expiry, standard claims, and algorithm. No signature verification.

Hex ↔ String / Decimal

Convert between hexadecimal, plain text, decimal byte values, and binary. Supports flexible hex formats (spaced, 0x-prefix, uppercase).

Date / Time

Unix Timestamp Converter

Convert between Unix timestamps and human-readable date/time.

Date Difference Calculator

Calculate the exact difference between two dates in years, months, days, hours, and more.

Timezone Converter

Convert a date and time to all major world timezones at once.

ISO 8601 Parser / Validator

Parse and validate ISO 8601 strings — dates, datetimes, durations, week dates, ordinal dates, and intervals.

Relative Time Calculator

Find how long until/since a date, or calculate a future/past date by adding days, months, hours, and more.

Cron Expression Parser

Explain cron expressions in plain English and preview the next execution times.

Format Conversion

YAML ↔ JSON Converter

Convert between YAML and JSON formats.

CSV ↔ JSON Converter

Convert between CSV and JSON formats.

JSON ↔ XML Converter

Convert JSON to XML and XML to JSON with full round-trip support. Handles nested objects, arrays, and primitive types.

SQL Formatter

Format and beautify SQL queries. Supports MySQL, PostgreSQL, SQLite, T-SQL, PL/SQL, and more.

TOML ↔ JSON Converter

Convert between TOML and JSON formats. Supports tables, arrays of tables, inline tables, and all TOML data types.

Markdown → HTML

Convert Markdown to HTML with a live preview. Supports GitHub-Flavored Markdown including tables, code fences, and strikethrough.

XPath Tester

Test XPath expressions against XML documents. Supports node selection, text extraction, attribute queries, and XPath functions.

Log Formatter

Parse and display NDJSON / JSON Lines log files. Auto-detects level, timestamp, message, and service fields with color-coded severity.

JSON Schema Generator

Generate a JSON Schema (Draft 7) from any sample JSON. Infers types, formats (email, date, URI), and required fields automatically.

JSON Formatter / Minifier

Beautify JSON with custom indentation, or minify it to a single line. Sorts keys optionally.

JSON Validator

Validate JSON instantly with detailed error messages, line/column indicators, and structure stats.

JSONPath Tester

Query JSON data with JSONPath expressions. Supports filters, wildcards, and recursive descent.

Hash / Security

Hash Generator

Generate MD5, SHA-1, SHA-256, and SHA-512 hashes.

UUID Generator

Generate UUID v4 or v7.

Password Generator

Generate secure random passwords with custom length and character sets.

HMAC Generator

Generate HMAC-SHA-1/256/384/512 signatures for API authentication and message integrity verification.

Network

cURL ↔ Fetch Converter

Convert cURL commands to JavaScript fetch code and vice versa.

Query Params ↔ JSON

Convert between URL query strings and JSON objects. Handles arrays and type coercion.

HTTP Header Formatter

Paste raw HTTP headers and get a clean, annotated table with descriptions for every field.

HTTP Status Code Reference

Look up all HTTP status codes (1xx–5xx) with descriptions and RFC references. Searchable and filterable.

CIDR Calculator

Calculate IPv4 subnet details from CIDR notation — network address, broadcast, usable hosts, subnet mask, and binary breakdown.

User Agent Parser

Parse any User-Agent string to detect browser, OS, rendering engine, and device type.

String

String Escape / Unescape

Escape or unescape special characters like \n, \t, and \".

Case Converter

Convert text between camelCase, PascalCase, snake_case, kebab-case, and more.

Regex Tester

Test regular expressions against a string and see matches highlighted in real time.

Slug Generator

Convert titles to URL-safe slugs. Supports Korean romanization, accent stripping, and custom separators.

Trim / Normalize Whitespace

Clean up text by trimming spaces, collapsing blank lines, normalizing line endings, and converting tabs.

Word / Character Counter

Count words, characters, sentences, paragraphs, and lines in real time. Shows reading time, unique words, average word length, and top word frequency.

Lorem Ipsum Generator

Generate lorem ipsum placeholder text by paragraphs, sentences, or words. Option to start with the classic opening or wrap output in HTML <p> tags.

Text Diff

Compare two texts and highlight additions and deletions line by line, word by word, or character by character.

Number / Base

Number Base Converter

Convert numbers between binary, octal, decimal, and hexadecimal instantly.

Byte / Storage Converter

Convert between bytes, KB, MB, GB, TB, and PB using both SI (÷1000) and binary (÷1024) standards.

IEEE 754 Float Converter

Visualize 32-bit and 64-bit IEEE 754 floating-point numbers as hex and individual bits.

Roman Numeral Converter

Convert between Arabic numbers (1–3999) and Roman numerals with a step-by-step breakdown.

Color

Color Converter

Convert colors between HEX, RGB, HSL, and OKLCH formats instantly.

Contrast Checker (WCAG)

Check the contrast ratio between two colors and verify WCAG AA / AAA accessibility compliance.

CSS Gradient Generator

Build linear CSS gradients visually with custom color stops, positions, and angle.

Color Palette Generator

Generate harmonious color palettes — analogous, complementary, triadic, tetradic, monochromatic, and Tailwind-style shades — from any base color.

Generators

QR Code Generator

Generate QR codes from any text or URL. Download as PNG or SVG.

Random String Generator

Generate cryptographically random strings with custom length, character sets, and quantity.

JSON Mock Generator

Build a schema visually and generate realistic mock JSON data with names, emails, dates, IDs, and more.

Image

Image → Base64 / Data URI

Convert any image to a Base64 string or Data URI for embedding directly in HTML or CSS.

Data URI ↔ File

Convert any file to a Base64 Data URI, or decode a Data URI back to a downloadable file.

EXIF Viewer / Stripper

View EXIF metadata embedded in photos (camera, GPS, settings) and download a privacy-safe stripped copy.

SVG Optimizer / Formatter

Format and minify SVG files in the browser. Remove comments, metadata, and empty attributes to reduce file size.

Image Compression

Compress JPEG, PNG, and WebP images directly in the browser using the Canvas API. Choose format, quality, and max dimensions.

About DevConverter

DevConverter is a free online toolbox built specifically for software developers and technical users. It provides instant access to the conversions and transformations that come up repeatedly in development work: decoding a Base64 string, figuring out what a Unix timestamp corresponds to, checking whether a JSON file is valid, generating a UUID, converting between YAML and JSON for a configuration file, or testing a regular expression against sample input.

The core design principle is privacy by default. Many tools that handle similar tasks require you to send your data to a remote server — which is a problem when the data in question is a JWT containing user information, an API key you are debugging, or a file with sensitive contents. DevConverter runs every computation in your browser using JavaScript, so the data never leaves your machine.

The site is built with Next.js and statically generated, meaning every page is a plain HTML file served from a CDN edge network. There is no application server to receive requests, which makes the privacy guarantee structural rather than a matter of trust. It also means the tools load quickly and remain functional even on slow connections.

Tools currently available span ten categories. The encoding tools handle Base64, URL encoding, Unicode escapes, JWT decoding, HTML entities, and several specialized binary encodings used in cryptography and distributed systems. The format conversion tools cover JSON, YAML, CSV, XML, TOML, SQL, and Markdown. The string tools include case conversion, regex testing, text diffing, and whitespace normalization. Additional categories cover hashing and password generation, number base conversion, date and time utilities, color conversion and accessibility checking, network tools, and image utilities.

Learn more about the project

Frequently Asked Questions

Is my data private?: Yes. All processing happens in your browser using JavaScript. Your input data — text, files, credentials, anything — is never transmitted to any server. We have no access to what you enter into the tools.
Do I need to create an account?: No. Every tool on the site is fully accessible without registration, login, or providing any personal information. Just open the page and start using the tool.
Are the tools accurate?: Yes, to the best of our ability. Tools use established browser APIs and well-tested open-source libraries where correctness is critical. For security-sensitive contexts (cryptographic hashes, JWT verification, encoding for production systems), always verify results independently.
Does DevConverter work offline?: After the initial page load, most tools continue to work without an internet connection because all logic runs in the browser. Some tools that render output to a canvas or use newer browser APIs may require a fresh load.
How many tools are available?: Currently over 60 tools across 10 categories: encoding and decoding, format conversion, string utilities, hash and security, number bases, date and time, color, generators, network utilities, and image tools. New tools are added regularly.
Can I suggest a new tool?: Yes. Send a brief description of what the tool should do and an example of the input and output to devconverter@proton.me. Tool requests that solve a common developer problem and can run entirely in the browser are most likely to be added.