Developer tools that work.
373 free utilities for code formatting, file conversion, online calculators, AI assistance, and more. No signup, no upload, no tracking.
Popular Tools
8 most-usedFree AI Chat - No Login, No Signup
Free AI chat powered by Groq and NVIDIA models. No login, no signup, no tracking. Coding, writing, math, brainstorming. Conversations stay in your browser.
Audio to Text Converter - Free Online Speech to Text
Free online audio to text converter. Convert speech to text in real-time with browser-based voice recognition. No uploads, no sign-up, 100% private.
Condom Size Calculator - Find Your Exact Fit
Free condom size calculator. Enter girth and length in mm, cm or inches to get your nominal width range and a fit verdict for any condom. 100% private.
Free Online Calculator - Scientific, Percent, BMI & Loan
More than a phone keypad: scientific functions, percent, loan payments and BMI in metric and imperial units. Free to use, no signup.
Free Email Signature Generator - Outlook Gmail HTML
Free email signature generator. 10 table-based templates, MSO compatible, base64 photo embedding, click-to-call phones, social icons. 100% private.
Image Compressor - Reduce Image File Size Online Free
Free online image compressor. Reduce image file size without losing quality. Supports JPG, PNG, WebP. No upload, privacy-first processing.
Image Cropper - Crop Photos with Aspect Ratio
Free online image cropper. Crop with aspect ratio presets, rotate, flip and zoom. Social media sizes for Instagram, Facebook and Twitter. No upload.
JSON Formatter - Format & Validate JSON
Free JSON formatter. Format, minify and beautify JSON, convert to and from YAML, and get the exact line of any syntax error. 100% browser, no upload.
Recently Updated
6 toolsCSS Specificity Calculator - Compute Selector Weight
Free CSS specificity calculator. Compute a,b,c values for any selector instantly. Understand selector weight and cascade priority. No signup.
NewHeart Rate Zone Calculator - 5 Zones by Age
Free heart rate zone calculator. Enter your age to get all five training zones in bpm, compare four max HR formulas, and find your personal Zone 2 range.
AI Code Reviewer - Free Online Code Review
Free AI code reviewer. Paste code, get instant review for bugs, performance, security, and best practices. No login, private.
NewPDF to Text Extractor - Free Online PDF Text Reader
Free PDF to text extractor. Extract plain text from any PDF in your browser. No upload, no signup, 100% private. Copy or download results.
NewMarkdown to PDF Converter - Free Online MD to PDF
Free online MD to PDF converter. Convert markdown to PDF instantly in browser. Preserve formatting, headings, code blocks, tables. No signup, 100% private.
NewKeyword Suggestions Generator - Free SEO Keyword Research
Free keyword suggestions from Google and Bing autosuggest. Expand one seed into 20 live search ideas, compare both engines, and copy the list. No signup.
NewBrowse by Category
11 categoriesView all 373 tools (alphabetical)
Free Sudoku - Daily Challenge & 4 Difficulty Levels
Free online Sudoku. 4 difficulty levels, daily challenge, hints with logic explanation, pencil notes and statistics. 100% private, no signup, no ads.
PopularFree Tarot Card Reading Online - Celtic Cross, Yes/No, Daily
Free tarot card reading online. 78 authentic Rider-Waite cards, 7 spreads (Daily, Yes/No, Past-Present-Future, Celtic Cross, Birth Card, Love, Career).
Free Text Diff Checker - Compare Text & Code Online
Free online text diff checker to compare text and code. Side-by-side view with syntax highlighting. Compare JSON, XML, code files and find differences.
Free Tile Calculator - Floor, Wall & Pattern Estimator
Free tile calculator with multi-room aggregation, 5 patterns, box optimization, grout and thinset estimator, waste factor. 100% private.
Free Time Zone Converter - World Clock
Free time zone converter. Convert time between cities instantly. See current time in multiple locations. No signup required.
Free Tip Calculator - Quick & Easy Restaurant Tip Tool
Free tip calculator for restaurants. Calculate tip amount, split bills, and see per-person cost. Works offline, no signup required. Instant results.
Free Typing Test - WPM, Accuracy & Code Mode
Free online typing test with WPM, accuracy and code snippet modes (JavaScript, Python, SQL, HTML). Practice words, quotes, numbers and syntax. No signup.
PopularFree URL Shortener - Shorten Long Links Instantly
Free URL shortener. Shorten long links instantly with no signup. Create clean, shareable short URLs for social media, messaging, and more.
Free Venn Diagram Maker - 2, 3, 4 Circles Online
Create 2, 3 or 4 circle Venn and Euler diagrams in your browser. Custom labels, colors, area-proportional sizing, SVG and PNG export. No signup.
PopularFree YAML Validator - Validate & Format YAML Online
Free YAML validator and formatter. Validate YAML syntax, fix errors with line numbers, and format YAML for better readability. No signup required.
Gamepad Tester - Test Controller and Stick Drift
Free online gamepad tester. Test every button, trigger and analog stick. Measure stick drift and deadzone. Export a diagnostic report. 100% private.
GIF Maker - Video & Images to GIF Free
Free GIF maker. Create animated GIFs from video or images. Trim, resize, FPS, loop, reverse. 100% private, no upload, no signup.
GIF to MP4 Converter - Free Online GIF to Video
Free GIF to MP4 converter. Convert animated GIFs to MP4 video files online. Reduce GIF file size by 90% with H.264 compression. 100% private, no upload.
Gold Price Tracker - Live Spot Gold Prices & Charts
Track live gold spot prices (XAU/USD). Free real-time gold price tracker with interactive charts. Updated every minute. No signup required.
GPA Calculator - 4 Scales, Semester, Cumulative & Target
Free GPA calculator with 4 scales, unlimited semesters, prior GPA integration, a target GPA planner, and Honors, AP and IB classes.
Grade Calculator - Weighted Average & Final Exam
Free grade calculator. Calculate weighted average grade, what you need on the final exam, and GPA. No signup, 100% private browser tool.
Graphing Calculator - Roots, Area & Fit
Free graphing calculator. Plot functions, polar, parametric and implicit curves, then get roots, turning points, area between curves, integrals and R2.
Habit Tracker - Free Daily Streak Builder
Free online habit tracker. Daily routines, streaks, heatmap, goals. No signup, 100% private. AI cannot track your habits - we do.
Hash Generator - MD5 SHA-1 SHA-256 SHA-512
Generate MD5, SHA-1, SHA-256 and SHA-512 hashes for any text or file, and compare two hashes to verify a download. Runs locally, nothing is uploaded.
Hashtag Generator - Instagram, TikTok, YouTube, Twitter
Free hashtag generator for Instagram, TikTok, YouTube, Twitter, LinkedIn and Facebook. Platform-aware rules, 6 categories, copy-all, live character count.
Heart Rate Zone Calculator - 5 Zones by Age
Free heart rate zone calculator. Enter your age to get all five training zones in bpm, compare four max HR formulas, and find your personal Zone 2 range.
HEIC to JPG Converter - Free iPhone Photo Converter
Free online HEIC to JPG converter. Convert iPhone HEIC photos to JPEG instantly in your browser. Batch convert unlimited photos. No upload, 100% private.
htaccess Redirect Tester - Test Rewrite Rules Online
Free htaccess redirect tester. Paste .htaccess rules and a URL, see which rule matched and why, and get the corrected line for the mistake.
HTML Entity Encoder/Decoder - Encode Special Characters
Free online HTML entity encoder and decoder. Encode special characters like &, <, > and quotes to HTML entities, and decode them back. 100%.
HTML Formatter - Format & Beautify HTML
Free HTML formatter. Beautify and minify HTML with correct indentation, and catch unclosed tags and invalid nesting before production. No upload.
HTML Playground - Live Code Editor Preview
Free HTML playground with live preview. Write and test HTML, CSS, JavaScript code instantly in your browser. No signup, 100% private.
HTML Table Generator - Visual Table Builder
Free HTML table generator. Create responsive HTML tables visually with editable cells, border styling, striped rows, and live preview. Copy clean HTML.
HTML to Image Converter - Free HTML to PNG, JPG, WebP
Free HTML to image converter. Paste HTML or CSS, render to PNG, JPG, or WebP with custom width, height, scale, and background. Full-page or viewport-only.
HTML to Markdown Converter - Free Online Tool
Free HTML to Markdown converter. Paste HTML, get clean Markdown. Supports tables, code blocks, links, images, nested lists, heading styles, and more. 100%.
HTML to PDF Converter - Free Online HTML to PDF
Free HTML to PDF converter. Paste HTML code, customize page size, orientation and margins. Live preview, download as PDF. No upload, 100% private browser.
HTTP Status & Header Checker Online
Free HTTP status checker. Check response codes, security headers, redirect chain, and response time for any URL. AI cannot check real HTTP headers - we do.
IBAN Validator and Checker - Validate Numbers
Free IBAN validator and checker. Validate International Bank Account Numbers with MOD-97 checksum. Supports 80+ countries. 100% private browser. No signup.
Image Color Picker - Pick Colors from Photo Online
Free online image color picker. Upload any photo and click to pick exact pixel colors. Get HEX, RGB, HSL, CMYK values instantly. No upload, 100% private.
Image Compressor - Reduce Image File Size Online Free
Free online image compressor. Reduce image file size without losing quality. Supports JPG, PNG, WebP. No upload, privacy-first processing.
PopularImage Cropper - Crop Photos with Aspect Ratio
Free online image cropper. Crop with aspect ratio presets, rotate, flip and zoom. Social media sizes for Instagram, Facebook and Twitter. No upload.
PopularImage Enhancer - Free Photo Quality Booster
Free image enhancer. Brightness, contrast, saturation, vibrance, sharpness, denoise, HDR and color temp in real time. 9 pro filters plus Auto Enhance.
PopularImage Extender - AI Outpaint & Uncrop Free Online
Free AI image extender. Outpaint & uncrop photos to 16:9, 9:16, 21:9, 1:1, social ratios with 5 fill algorithms. No signup, 100% private.
Image Format Converter - Free Online JPG PNG WebP Converter
Free online image format converter. Convert between JPG, PNG, WebP, GIF, BMP, TIFF instantly. No upload, 100% private, browser-based conversion.
Image to Base64 Converter - Encode Images Online Free
Free online image to base64 converter. Convert any image to base64 string, data URI, HTML img tag, or CSS url(). Supports PNG, JPG, WebP, GIF. 100%.
Image to Excel Converter - Free JPG PNG to XLSX Online
Free image to Excel converter. Convert JPG, PNG, WebP, HEIC photos, scanned tables and screenshots to editable XLSX. Auto-detect rows and columns.
Image to PDF - Convert JPG PNG WebP HEIC to PDF Free
Free image to PDF converter. Combine JPG, PNG, WebP, HEIC, BMP, GIF into one PDF. Page size, orientation, margins. No upload, 100% private.
PopularImage to Word Converter - Free JPG PNG to DOCX Online
Free image to Word converter. Convert JPG, PNG, WebP, GIF, BMP, HEIC photos into editable DOCX, RTF, or TXT. 12+ languages, batch OCR, 100% private.
Image Upscaler - AI Enhance Photos to 4K
Upscale images to 2x, 3x or 4x with edge-aware sharpening and denoise controls so photos stay sharp. In your browser, no upload, no signup.
Image Vectorizer - Free PNG JPG to SVG Converter Online
Free image vectorizer. Convert PNG, JPG, WebP, BMP and GIF to scalable SVG in your browser. 9 presets plus color count, blur and threshold. No upload.
PopularImage Watermark - Add Text and Logo to Photos
Free online image watermark tool. Add text or logo watermarks to protect your photos. Custom position, opacity, rotation, tile mode, font, color. 100%.
Income Tax Calculator 2026 - US India UK
Free income tax calculator 2026 with US federal, India new/old regime, and UK brackets. No signup, private. AI gives wrong tax brackets.
Inflation Calculator - CPI Dollar Adjuster
Adjust any dollar amount for real US inflation with official monthly CPI data since 1913. Shows exact indexes used. 100% private.
Investment Calculator - Profit and Portfolio Tracker
Free investment calculator with portfolio tracker. Calculate stock profit, ROI, dividend yield, and average cost basis across multiple lots. No signup.
IP Address Lookup - Find Your IP Address
Find your public IP address, then the ISP, country, city and connection type behind it. Paste any address to look it up too. No signup, lookups not stored.
Is It Down? - Website Down Checker
Free website down checker. Check if any website is down for everyone or just you. Real-time status, response time, and HTTP code. No signup, 100% free.
Frequently Asked Questions
Are all 373 developer tools really free?
Yes — every tool on DevTools Hub is 100% free with no signup, no trial, no daily limit, and no watermark. The site is supported by optional cloud functions and ad-free by design.
Do you upload my data to a server?
Most tools process everything in your browser. Only AI-backed tools (AI Chat, AI Detector, Image Generator, Story Animator, Translator, Paraphrasing Tool, Plagiarism Checker, Resume Builder, Cover Letter Generator, Citation Generator, ATS Resume Checker, AI Humanizer, Text-to-Speech, Text-to-Video, Text Summarizer, Math Solver, Grammar Checker, Subtitle Generator, and a few others) call a server API for GPU compute. Uploads are transient and never logged. Each tool page documents exactly what leaves your device.
Why use these tools instead of asking an AI chatbot?
AI chatbots hallucinate exact arithmetic, produce invalid JSON/XML, drop SVG attributes, and cannot compute dates, fractions, or compound interest reliably. DevTools Hub uses deterministic code — same input always yields the same verified output.
Do I need to create an account?
No account, no email, no tracking cookies. Open any tool, use it, close the tab. Your inputs never leave your browser unless you explicitly call a cloud-backed AI tool.
How often are new tools added?
New tools ship 2-3 times per week. The homepage shows a 373 tool count that updates automatically as new entries are added to the public manifest. See the sitemap.xml for the complete list.
Can I use these tools commercially?
Yes. The outputs you generate belong to you — use them in client work, internal tools, or commercial products without attribution. The tool code itself is MIT-licensed on GitHub.