Free Online Developer Tools

Format, validate, and minify JSON with real-time error detection. See structure stats. Free online JSON formatter for developers.

Compare two JSON objects side by side, highlight added and removed keys, and inspect changed values instantly with a fast online JSON diff tool.

Format and beautify SQL queries online with cleaner indentation for SELECT, INSERT, UPDATE, DELETE, and JOIN statements.

Fix SQL output where string values are missing quotes. Paste your query and get valid SQL with properly quoted strings.

Convert CSV data into SQL INSERT statements for ANSI, MySQL, or PostgreSQL.

Validate JSON against a schema online, inspect path-based errors, and test required fields, enums, patterns, arrays, and nested objects.

Repair invalid JSON by fixing common mistakes like single quotes, trailing commas, and bare keys. Free online JSON fixer.

Convert JSON to YAML online with clean indentation, nested object support, and browser-based processing that keeps your data private.

Convert YAML to JSON online with support for nested keys, arrays, booleans, and quoted values, all processed directly in your browser.

Format and validate YAML with instant syntax checking. Round-trips through safe parser.

Format and prettify XML online with readable indentation, browser-side validation, and cleaner structure for debugging, editing, and review.

Convert XML to JSON online with support for attributes, nested elements, repeated nodes, and mixed content in a developer-friendly structure.

Convert table data between CSV, Markdown, HTML tables, and SQL INSERT statements with automatic format detection in your browser.

Paste CSV data and explore it in a sortable table. Auto-detects delimiter and preserves quoted values. Free online CSV viewer.

Convert CSV data to JSON instantly. Auto-detect delimiter, preserve headers, and export clean formatted JSON in your browser.

Convert JSON arrays and nested objects to CSV online, flatten records into spreadsheet-ready rows, and export clean comma-separated data instantly.

Convert JSON samples to TypeScript interfaces, Zod schemas, Go structs, or Python dataclasses.

Convert text between camelCase, snake_case, PascalCase, kebab-case and more. Free online case converter for developers.

Count words, characters, sentences, and lines in your text. Free online text statistics tool for writers and developers.

Reverse text by characters, words, or lines online, then copy the result instantly for debugging, data cleanup, or formatting tasks.

Find and replace text with support for regex, case-sensitive, and whole word matching. Free online find and replace tool.

Convert text into clean URL-friendly slugs instantly. Remove punctuation, accents, and extra spaces. Free online slug generator.

Escape or unescape strings for JavaScript, JSON, Java, C#, shell, CSV, HTML, and XML.

Compare two texts and see the differences highlighted. Side-by-side and inline diff views. Free online text comparison tool.

Write Markdown and preview the rendered output live, with support for headings, lists, code blocks, links, and quick HTML conversion.

Convert Markdown to clean HTML instantly. Paste Markdown and copy production-ready HTML. Free online Markdown to HTML converter.

Build Markdown tables with a spreadsheet-like editor. Add rows/columns and set alignment.

Generate a table of contents from Markdown headings with anchor links.

Encode and decode Base64 strings instantly. Supports text and file encoding. Free online Base64 converter for developers.

Convert images to Base64 strings with drag and drop. Copy raw Base64 or full data URLs instantly. Free online image to Base64 converter.

Convert Base64 strings or data URLs back into previewable images online, inspect the output instantly, and download the decoded result.

URL encode or decode text online with encodeURI and encodeURIComponent modes, plus instant handling for query strings, paths, and full URLs.

Encode or decode HTML entities online, including named, decimal, and hex entities, so you can safely work with special characters in markup.

Escape and unescape Unicode characters online for JavaScript, Python, CSS, and HTML formats, with quick copy-ready output for each style.

Create and sign JWT tokens online with HS256 by entering a header, payload, and secret, then copy the generated token instantly.

Decode JWT tokens online, inspect header and payload claims, review expiry timestamps, and read signatures safely in your browser.

Hash passwords online with SHA-256, SHA-384, or SHA-512, add an optional salt, and inspect deterministic output directly in your browser.

Generate cryptographically secure random passwords with custom length and character sets. Free online password generator.

Check password strength online with entropy, crack-time estimates, and practical suggestions to improve weak passwords quickly.

Generate HMAC signatures online with SHA-256, SHA-384, or SHA-512 by entering a message and secret key directly in your browser.

Generate MD5, SHA-1, SHA-256, SHA-384, and SHA-512 hashes from text instantly. Free online hash generator for developers.

Generate OAuth 2.0 PKCE code verifier, challenge (S256), and state.

Encrypt or decrypt text with AES-GCM 256 using a password-derived key (PBKDF2).

Generate RSA-OAEP keypairs (2048/3072/4096) as PEM, client-side.

Convert a multi-line list to comma-separated values. Choose separator and formatting options. Free online list converter.

Convert a list to quoted strings for SQL IN clauses, APIs, or scripts with single or double quotes, custom separators, and optional wrapping.

Compare two lists and find unique items, common items, differences. Set operations: union, intersection, A only, B only.

Remove duplicate items from a list. Case sensitive or insensitive. Preserve original order or sort alphabetically.

Turn indented text into clean bullet lists or hierarchical numbered outlines online, preserving nesting for documentation and planning.

Sort text lines online alphabetically or numerically, reverse the order, trim spaces, remove blanks, and dedupe repeated lines in one step.

Split rows of data by a delimiter such as comma, semicolon, tab, or any custom character. Trim values, remove empties, and pick an output separator.

Split a comma-separated string or list of items into N evenly sized chunks. Default 2 chunks. Free online list chunker for developers.

Generate UUID v4 (random) and v7 (time-based) UUIDs. Inspect and validate existing UUIDs. Free online UUID generator.

Generate random strings with custom length, character sets, and quantity. Perfect for passwords, tokens, and test data.

Generate Lorem Ipsum placeholder text by paragraphs, sentences, or words. Free dummy text generator for designers and developers.

Create custom-sized blank images with chosen width, height, DPI, background color, and text in pixels, centimeters, or inches.

Generate ULIDs — 128-bit lexicographically sortable unique identifiers.

Generate URL-safe random Nano IDs with configurable length.

Generate mock records with typed fields as JSON, CSV, or SQL.

Generate QR codes for URLs, text, or any payload. Configurable size, margin, error correction, and colors. Download PNG.

Decode QR codes from an image. Runs entirely in your browser; images never leave your device.

Convert CSV/TSV data to bordered ASCII tables or upload images to generate ASCII art. Free online ASCII art generator.

Convert between inches, centimeters, meters, feet, yards, kilometers, and miles instantly with a simple browser-based length converter.

Convert between kilograms, grams, milligrams, pounds, ounces, and tonnes instantly with a fast browser-based weight converter.

Convert numbers between binary, octal, decimal, and hexadecimal online with instant cross-updates for debugging, low-level work, and programming tasks.

Convert HEX, RGB, and HSL colors online, fine-tune values with a live picker, and copy formats ready for CSS, design systems, or UI work.

Convert temperatures between Celsius, Fahrenheit, Kelvin, and Rankine with instant two-way updates.

Convert between bytes, kilobytes, megabytes, gigabytes, and more in both decimal (KB) and binary (KiB) units.

Convert between square meters, square feet, acres, hectares, and more area units instantly.

Convert liters, gallons, milliliters, cubic meters and other volume units with live two-way sync.

Convert speed between mph, km/h, m/s, knots, and more with live calculation.

Convert durations between milliseconds, seconds, minutes, hours, days, and weeks.

Convert angles between degrees, radians, gradians, and turns with real-time updates.

Convert numbers to Roman numerals and back (1–3999). Fast, private, client-side.

Convert numbers into written English words. Handles big numbers, negatives, and decimals.

Use a fast online calculator with keyboard support, instant expression evaluation, and history for everyday math and quick calculations.

Estimate how much car you can afford using the 20/5/10 rule with salary, down payment, existing EMIs, interest rate, and loan tenure.

Calculate tank volume for rectangular, cylindrical, spherical, and oval tanks. Supports partial fill levels. Results in liters, gallons, cubic meters.

Calculate Body Mass Index with metric or imperial units.

Calculate daily calorie needs (TDEE) and macronutrient splits.

EMI calculator with cumulative payment chart, principal-vs-interest donut, smart insights on the crossover month, prepayment savings, and a shareable 1080×1080 snapshot.

Fixed deposit maturity, effective yield, growth chart, TDS alert, and a downloadable square snapshot — with quarterly/monthly/half-yearly/yearly compounding.

PPF calculator with growth chart, maturity breakdown donut, 80C insights and a shareable 1080×1080 snapshot — see tax-free corpus and 5-year extension impact.

SIP calculator with growth chart, corpus breakdown donut, and smart insights — see your wealth multiple, doubling point, and step-up impact instantly.

Recurring deposit maturity with growth chart, deposited-vs-interest donut, step-up and extension comparisons, TDS alert, and a downloadable square snapshot.

Project a mutual fund lumpsum with growth chart, invested-vs-gains donut, doubling-year insight, SIP-equivalent comparison, and a downloadable shareable snapshot.

Calculate simple interest with a growth chart, smart comparisons against compound interest, doubling period, and a downloadable shareable snapshot.

Compound interest with yearly/quarterly/monthly/daily compounding, effective rate, growth chart, Rule-of-72 insights, and a downloadable shareable snapshot.

See how inflation changes prices and purchasing power — cost growth chart, price-doubling time, real-return target, and a downloadable square snapshot.

Build a month-by-month loan amortization schedule with principal, interest, and balance.

Check the current time across major world timezones including UTC, IST, EST, PST, GMT, and JST with a live updating world clock.

Convert time between any major timezone. Edit any timezone and all others update instantly. Free online timezone converter.

Convert between Unix timestamps, ISO 8601, and human-readable dates. Shows relative time. Free online timestamp converter.

Calculate the exact difference between two dates in days, weeks, months, years, and business days, with future and past date handling.

Pick colors online, convert between HEX, RGB, and HSL, and copy CSS-ready values instantly for design and frontend work.

Generate color palettes from any base color, including complementary, analogous, triadic, monochromatic, shades, and tint variations.

Check color contrast ratios online for WCAG AA and AAA compliance, including normal text, large text, and accessible color combinations.

Build linear and radial CSS gradients with live preview and copy-ready code.

Design CSS box shadows with offset, blur, spread, inset, and color controls.

Create CSS border-radius values with independent per-corner control.

Edit CSS cubic-bezier easing curves with a visual handle editor.

Test regular expressions with instant match highlighting. Supports global, case insensitive, multiline, and dotall flags.

Convert cURL commands into Python requests, JavaScript fetch, and Go HTTP code instantly. Free online cURL to code generator.

Browse HTTP status codes with meanings, categories, and practical explanations. Search by code or phrase. Free online reference.

Press any key to inspect key, code, keyCode, which, location, and modifier states instantly with this online keyboard event tester.

Calculate Linux file permissions. Toggle rwx bits or enter octal codes to see symbolic and numeric equivalents.

Look up MIME / content types by file extension. Searchable list of common web and media types.

Calculate IPv4 subnet details: network address, broadcast, host count, and mask.

Convert IPv4 addresses between decimal, binary, hex, and integer. Expand and compress IPv6.

Validate card numbers with Luhn checksum and detect the card brand. Numbers never leave your browser.

Validate IBAN numbers with country-length and mod-97 checksum.

Validate email syntax and flag disposable providers. Runs client-side.

Parse URLs into protocol, host, port, path, query parameters, and hash fragments, then inspect decoded query strings in a readable table.

Parse user agent strings to identify browser, version, OS, device type, engine, bot detection, and mobile status online.

Minify CSS instantly. Strips comments and whitespace while preserving correctness.

Minify JavaScript by stripping comments and extra whitespace. Client-side, private.

Parse raw HTTP response headers and surface security header status.

Minify HTML online by removing comments, extra whitespace, and unnecessary markup while checking the compression savings instantly.

Preview HTML code live in your browser, render full documents or fragments instantly, and test markup changes without leaving the page.

Convert HTML into clean GitHub-flavored Markdown client-side.

Generate Open Graph and Twitter card meta tags with live preview.

Generate robots.txt rules for allow, disallow, crawl-delay, and sitemaps.

Generate XML sitemaps for submission to search engines.