Free Online Developer Tools
Validate JSON and XML, encode and decode URLs and Base64, inspect JWTs, generate slugs, and analyze SEO — all directly in your browser with no upload and no account required.
Barcode Generator
Generate Code 128, Code 39, EAN-13, EAN-8, UPC-A, and ITF-14 barcodes in your browser. Customize size and color, then download as PNG.
DeveloperBase Converter
Convert numbers between binary, octal, decimal, hex, and any base from 2 to 36.
DeveloperBase64 Encoder
Encode plain text or decode Base64 strings instantly in your browser. Supports UTF-8, Latin-1, and URL-safe Base64 variant.
DeveloperBase64 to Image
Decode a Base64 string or data URI back into a viewable image. Supports plain Base64 with manual MIME type selection, URL-safe Base64, and direct data URI input. Preview and download the result.
DeveloperBox Shadow Generator
Visually build CSS box-shadow effects with multiple layers, live preview, and one-click copy or download.
DeveloperChart Maker
Create bar, line, pie, doughnut, polar, and radar charts online. Edit data in an interactive table, customize colors, and download as PNG.
DeveloperCode Screenshot
Turn your code into a beautiful, shareable screenshot. Choose themes, backgrounds, fonts and export as PNG or JPEG — all in your browser.
DeveloperCSS Button Generator
Design and generate CSS buttons with custom colors, gradients, animations, shadows, and more. Copy code instantly.
DeveloperCSS Formatter
Beautify or minify CSS code instantly in your browser. Supports at-rules, custom properties, url() values, and licence comment preservation.
DeveloperCSS Gradient Text
Create beautiful gradient text effects and instantly get the CSS code. Customize colors, angle, font size and weight — live preview included.
DeveloperCSS Grid Generator
Visually build CSS Grid layouts — configure columns, rows, gap and alignment, then copy the generated CSS or HTML.
DeveloperCSV to JSON
Convert CSV files to JSON with auto-delimiter detection, type coercion, and three output formats: array of objects, array of arrays, or keyed by first column.
DeveloperGlassmorphism Generator
Design frosted-glass CSS panels with live preview — adjust blur, tint, border, and shadow, then copy the ready-to-use CSS in one click.
DeveloperHash Generator
Compute MD5, SHA-1, SHA-256, SHA-384, and SHA-512 hashes from text or binary files. Multiple algorithms at once, file drag-and-drop, and one-click copy.
DeveloperHTML Formatter
Beautify or minify HTML code instantly in your browser. Paste markup, load a file, pick 2-space, 4-space, or tab indentation, and format or compress in one click. No upload, no signup.
DeveloperHTML to Image
Convert any HTML and CSS snippet into a PNG, JPG, or WebP image. Set the render width, pixel scale, and background, then download — no upload required.
DeveloperHTML to Markdown
Convert HTML into clean Markdown. Paste any HTML and get GFM-compatible Markdown with table support instantly — no server, no upload.
DeveloperHTML to Text
Strip HTML tags and convert HTML documents to clean plain text. Supports link URLs, alt text, list bullets, entity decoding, and heading styles.
DeveloperImage to Base64
Encode any image to a Base64 string with five output formats: data URI, plain Base64, CSS background-image, HTML img tag, and Markdown. Drag and drop, file picker, or clipboard paste supported.
DeveloperJavaScript Formatter
Beautify or minify JavaScript code instantly in your browser. Handles regex literals, template literals, strings, and preserves licence comments during minification.
DeveloperJSON Formatter
Format, beautify, or minify JSON instantly in your browser. Validates syntax with line-level error reporting, supports key sorting, and lets you copy or download the result.
DeveloperJSON to CSV
Convert JSON arrays and objects to CSV with a custom delimiter, quote character, and newline style. Supports nested object flattening, header row toggle, and CSV file download.
DeveloperJSON to YAML
Convert JSON to YAML and YAML to JSON instantly in the browser — with syntax support for nested objects, arrays, and all scalar types.
DeveloperJSON Tree Viewer
Visualise any JSON as an interactive collapsible tree. Expand nodes, copy key paths, detect types by colour, and validate JSON instantly in your browser.
DeveloperJWT Decoder
Decode and inspect JWT tokens instantly in the browser — view header, payload claims, expiry status, and signature without sending data to a server.
DeveloperKeyword Density Checker
Analyse keyword frequency and density in any text. Supports 1-word, 2-word, and 3-word phrase analysis with stop word filtering, frequency bars, and CSV export.
DeveloperLink in Bio Builder
Create a polished link-in-bio page with avatar, themed button links, and icon picker support. Export a standalone HTML file in seconds.
DeveloperMarkdown to HTML
Convert Markdown to HTML with a live preview. Switch between rendered output and HTML source, copy the result, or download a complete HTML file.
DeveloperMeta Tag Generator
Generate complete HTML meta tags: SEO basics, Open Graph, Twitter Card, and technical tags. Copy or download the snippet instantly.
DeveloperNeumorphism Generator
Create soft-UI neumorphic CSS elements with live preview — adjust color, shadows, blur, and shape style, then copy the ready-to-use CSS instantly.
DeveloperReadability Checker
Analyse text readability with six formulas: Flesch Reading Ease, Flesch-Kincaid Grade, Gunning Fog, Coleman-Liau, SMOG, and ARI. Flags long sentences and shows detailed stats.
DeveloperRegex Tester
Test regular expressions in real time with live match highlighting, capture group details, and a Replace mode for previewing substitutions.
DeveloperRobots.txt Generator
Generate a valid robots.txt file with custom User-Agent blocks, Allow/Disallow rules, crawl-delay, and sitemap URL.
DeveloperSchema Markup Validator
Validate JSON-LD structured data in your HTML for correctness and Google Rich Result eligibility. Get instant feedback on required and recommended properties for 20+ schema types.
DeveloperSEO Analyzer
Paste your page HTML and get an instant on-page SEO report. Checks title, meta description, headings, images, links, Open Graph tags, structured data, and more.
DeveloperSERP Preview
Preview how your page title, URL, and meta description will look in Google search results. Live desktop and mobile SERP card with character counters and SEO tips.
DeveloperSitemap Generator
Generate a valid XML sitemap from a list of URLs with changefreq, priority, and lastmod options.
DeveloperSQL Formatter
Beautify or minify SQL queries instantly in your browser. Supports keyword casing (UPPER/lower), custom indentation, comments, named parameters, and all major SQL dialects.
DeveloperSVG Pattern Generator
Create seamless SVG tile patterns — dots, grids, zigzag, checker and more — then export as SVG or CSS background-image.
DeveloperText to HTML
Convert plain text to valid HTML markup. Detect paragraphs, headings, lists, bold, italic, and links automatically.
DeveloperTimestamp Converter
Convert Unix timestamps to human-readable dates and convert dates back to timestamps. Supports seconds, milliseconds, microseconds, nanoseconds, and 60+ IANA timezones.
DeveloperTyping Speed Test
Measure your typing speed and accuracy with real-time WPM tracking, error highlighting, and timed tests from 15 to 120 seconds.
DeveloperURL Encoder
Percent-encode text for safe use in URLs or decode percent-encoded strings instantly in your browser. Supports encodeURIComponent and encodeURI modes.
DeveloperUUID Generator
Generate UUID v4 (random) and UUID v7 (time-ordered) identifiers in bulk. Supports standard, uppercase, no-hyphens, and braces formats with one-click copy.
DeveloperWhiteboard
Free online whiteboard — draw, sketch, and annotate in your browser with freehand pen, shapes, eraser, undo, and PNG download. No login or install needed.
DeveloperWord Frequency Analyzer
Count how often each word and character appears in any text. Three analysis tabs: word frequency, character frequency, and word length distribution. Sortable with CSV export.
DeveloperXML Formatter
Beautify or minify XML documents instantly in your browser. Handles processing instructions, CDATA sections, DTD declarations, and warns on malformed XML.
DeveloperFree Developer Tools brings together a set of browser-based utilities covering the most common tasks that arise during web development, content publishing, and search engine optimization. The collection includes tools for validating data formats, encoding and decoding strings, inspecting tokens, and analyzing how a page is seen by search engines — all without installing a single dependency.
What the Developer Tools Cover
The tools in this category address practical everyday tasks. You can validate and format JSON or XML to catch syntax errors before they reach production, encode and decode URL-encoded strings or Base64 payloads, inspect and decode JWT tokens to verify their structure, and generate clean slugs from arbitrary text. Each tool accepts plain input and produces immediate, formatted output you can copy directly into your code or configuration.
SEO Tools for Better Visibility
A significant part of this category is dedicated to search engine optimization. Search visibility begins with the basics: well-formed title tags, descriptive meta descriptions, correct canonical links, and structured data that search engines can parse. The SEO tools in this collection let you preview how a page appears in Google search results, check Open Graph tags for social sharing accuracy, analyze meta tag completeness, and inspect robots directives — all without a third-party platform. Whether you are optimizing a landing page, auditing a blog post, or debugging why a shared URL renders the wrong thumbnail, these tools give you direct answers in seconds. Good SEO is not only about keywords; it begins with technically correct markup, and these tools help you verify that quickly.
Built for Speed and Privacy
All processing happens entirely in your browser. No data — whether it is a JSON payload containing API keys, a JWT with user claims, or a URL with internal query parameters — is ever sent to an external server. This matters in development environments where information is often sensitive and should not pass through third-party services.
Practical Across Many Roles
Developer tools are needed by a wide range of people: backend engineers debugging API responses, front-end developers formatting data, content teams optimizing page metadata, and SEO specialists auditing large sites. This collection serves all of those users with tools that are simple enough to use quickly and thorough enough to be genuinely useful.
Frequently Asked Questions
Are these developer tools free?
Yes. Every tool in this category is completely free with no usage limits or premium tiers.
Is my data kept private?
Yes. All processing runs locally in your browser. Sensitive data such as tokens, API keys, or internal URLs is never sent to any server.
What SEO tools are included?
The category includes tools for previewing search snippets, checking meta tags, inspecting Open Graph data, and validating structured markup, helping you improve both technical SEO and social sharing.
Do the tools work on mobile?
Yes. All developer tools are responsive and work on modern mobile browsers including Chrome for Android and Safari for iOS.