Developer tools that work.
245 free utilities for code formatting, file conversion, calculations, AI assistance, and more. No signup, no upload, no tracking.
Popular Tools
8 most-usedAnagram Solver & Word Unscrambler - Free
Free anagram solver. Enter letters (use ? for blanks) to find every valid word from a 168K-word dictionary with Scrabble scores. No signup.
NewFree AI Chat - No Login, No Signup
Free AI chat powered by Llama 3.3 70B. No login, no signup, no tracking. Coding, writing, math, brainstorming. Conversations stay in your browser.
NewFree Online Calculator - Math Problem Solver
Free online calculator with scientific functions, unit conversion, loan calculator, and BMI calculator. No signup required, works in any browser.
Calorie Calculator - Free TDEE BMR & Macro Calculator
Free calorie calculator. Calculate your TDEE, BMR, and optimal macros for weight loss, maintenance, or muscle gain. Mifflin-St Jeor equation, no signup, 100% private. AI cannot compute accurate metabolic formulas.
NewColor Blindness Simulator - CVD Test
Free color blindness simulator. Test images and colors with 8 types of color vision deficiency (protanopia, deuteranopia, tritanopia, achromatopsia). WCAG accessibility tool for designers and developers. No signup, 100% private browser processing.
NewFree Email Signature Generator - Outlook Gmail HTML
Pro email signature generator. 10 table-based templates, MSO compatible, base64 photo embedding, click-to-call phones, social icons. Outlook + Gmail + Apple Mail ready. No signup, no tracking, 100% private browser tool. AI cannot produce email-client-compatible HTML.
NewIBAN Validator & IBAN Checker - Validate Bank Numbers
Free IBAN validator. Validate International Bank Account Numbers with MOD-97 checksum. 80+ countries, batch validation, test IBAN generator. 100% private, no data uploaded. No signup.
NewPoker Odds Calculator - Texas Hold'em Equity
Free poker odds calculator. Exact hand-vs-hand equity by full enumeration, not Monte Carlo. Board cards, up to 3 players, call/fold helper. No signup.
NewRecently Updated
2 toolsAudio Cutter & Trimmer
Free online audio cutter and trimmer. Cut and trim MP3, WAV, M4A, FLAC, OGG with waveform precision. No upload, 100% private.
Grade Calculator - Weighted Average, Final Exam & GPA
Free grade calculator. Calculate weighted average grades, what you need on the final exam, and GPA. No signup, 100% private browser tool. AI gets grade math wrong - we don't.
NewBrowse by Category
11 categoriesView all 245 tools (alphabetical)
Microphone Test - Free Online Mic Tester & Audio Checker
Free online microphone test. Measure mic levels, detect clipping and noise, play back your voice, get a verdict and report. No signup, 100% private.
NewMock Data Generator - Free Fake Test Data Online
Free mock data generator. Generate realistic fake test data as JSON, CSV, or SQL. Presets for users, products, companies, addresses, blog posts, transactions. No signup, 100% private browser tool. AI cannot generate consistent test data - we do.
NewMonitor Test - Dead Pixel & Refresh Rate Tester Online
Free online monitor test. Full-screen patterns find dead pixels, stuck pixels, backlight bleed, banding, ghosting and geometry faults. Measure the real refresh rate in Hz, guided wizard, exportable report. No signup, 100% private.
NewMorse Code Translator - Encode/Decode Morse Code
Free Morse code translator. Encode text to Morse code and decode Morse back to text. Instant conversion, audio playback, and copy functionality.
Mortgage Calculator with PMI, Tax & Insurance
Free mortgage calculator with PMI, property tax, insurance, HOA. Shows true monthly payment, total cost, amortization schedule, and affordability.
NewMouse Tester - Test Mouse Buttons Online Free
Free online mouse tester. Test every button, detect double-click chatter, scroll faults, polling rate and movement. Export a report. No signup.
NewNumber to Words Converter - Spell Out Numbers in English
Free number to words converter. Convert any number to English words for checks, invoices, legal docs. Supports decimals, currency, lakh/crore. 100% accurate. No signup.
NewOn This Day in History - Historical Events & Famous Births
Discover what happened on this day in history. Free database of major historical events, famous births, notable deaths, and holidays. Updated daily. No signup.
NewOnline Chart Maker - Bar, Line, Pie & Radar
Free online chart maker and graph generator. Create bar, line, pie, doughnut, and radar charts with customizable colors and data. Export PNG. No signup, 100% private browser processing. AI cannot draw accurate charts - we do.
NewOnline Guitar Tuner - Free Mic Guitar Tuner
Free online guitar tuner. Tune by microphone with real-time pitch detection and cent-precision needle. 8 tunings plus Bass, Ukulele, Violin. 100% private.
NewOnline Metronome - Free BPM Beat & Practice Tool
Free online metronome with tap tempo, time signatures, subdivisions, and visual beat indicator. Practice with precision timing for any instrument. 100% browser-based, no signup.
NewP-Value Calculator - Hypothesis Test & Z, T, Chi-Square
Free p-value calculator. Run z-test, t-test (one/two-sample/paired), chi-square, linear regression and confidence interval. Exact p-values, step-by-step. No signup, 100% private.
NewPassport Photo Maker - Free Online 2x2, 35x45mm, 35x35mm
Free online passport photo maker. Create compliant US 2x2, Schengen/UK 35x45mm, India 35x35mm, China 33x48mm photos. Auto white background, print sheet (4x6/A4), 100% private browser processing.
NewPassword Generator - Create Strong Passwords
Generate strong, secure passwords with real-time strength analysis. Learn what makes a password secure.
PopularPassword Strength Checker - Analyze & Test Password Security
Free online password strength checker with entropy, crack time estimation for 3 scenarios, character analysis, and breach check via HIBP k-anonymity. 100% private browser. No signup.
NewPDF Compressor - Free Online File Size Reducer
Free PDF compressor with 4 levels (light, medium, strong, aggressive). 100% private browser processing, no upload, no signup, no daily limit, no watermark. AI cannot process binary PDFs.
NewPDF Editor - Edit, Rotate, Delete, Annotate PDF Pages
Free online PDF editor. Rotate, delete, reorder pages, add text annotations, crop, and extract pages. No upload required - works entirely in your browser.
PDF Merger - Combine Multiple PDFs into One
Free online PDF merger. Combine multiple PDF files into one with drag-drop reordering, visual preview, and compression. No upload limit. Works in browser.
PDF Page Numbers - Add Page Numbers to PDF Free Online
Free PDF page number adder. Add page numbers to any PDF - Arabic or Roman format, 9 positions, custom prefix, skip cover. 100% private, no upload.
NewPDF Redactor - Permanently Redact PDF Online Free
Free PDF redactor. Search-and-redact text, draw boxes, auto-detect emails, phones, credit cards, SSN. 100% client-side. AI cannot redact binary PDFs.
NewPDF to Excel Converter - Free Online PDF to XLSX
Free online PDF to Excel converter. Extract tables and data from PDF to XLSX or CSV. Smart position-based table detection, multi-page support, editable preview. 100% private, no upload, no signup, unlimited, no watermark. AI cannot parse binary PDFs or generate valid XLSX files - this real pipeline does.
NewPDF to Image Converter - Free Online JPG PNG WebP
Free PDF to image converter. Convert PDF pages to JPG, PNG, or WebP. Choose DPI (72-300), quality, page range. Preview thumbnails, 100% private browser processing, no upload, no signup, no watermark.
NewPDF to Word Converter - Free DOCX Online
Free PDF to Word converter. Extract text from PDF to editable DOCX, RTF, or TXT. 100% private browser processing, no upload, no signup, no daily limit, no watermark. AI cannot generate valid .docx files.
NewPDF Unlocker - Remove Password Online Free
Free online PDF unlocker. Remove password protection from PDF files entirely in your browser. AES-128/256, no upload, no signup, no daily limits. 100% private. AI cannot unlock encrypted PDFs - we do.
NewPDF Watermark - Add Text Watermark to PDF Free Online
Free online PDF watermark tool. Add CONFIDENTIAL, DRAFT, or custom text watermarks. Full control over font, size, color, opacity, rotation, position & tile mode. 100% private, no upload, no signup.
NewPercentage Calculator - Find %, Increase, Decrease & Difference
Free percentage calculator online. Calculate X% of Y, increase/decrease, reverse percentage, and add/subtract percent. Instant results, no signup.
Photo Collage Maker - Free Online Image Combiner
Free online photo collage maker. Combine multiple images into beautiful collages with 8 layout templates, custom spacing, background color. No signup, no upload, 100% private browser processing. AI cannot create visual collages - we do.
NewPoker Odds Calculator - Texas Hold'em Equity
Free poker odds calculator. Exact hand-vs-hand equity by full enumeration, not Monte Carlo. Board cards, up to 3 players, call/fold helper. No signup.
NewPrinter Test Page - Print Quality Diagnostic
Free printer test page. Print color, CMYK, nozzle, banding, alignment and text sharpness sheets to diagnose HP, Epson, Canon & Brother printers. No signup.
NewProxy Checker - Free IP Proxy Detection Tool
Free online proxy checker. Detect if an IP address is a proxy, VPN, or Tor exit node. Check IP geolocation, WHOIS, and open proxy ports.
QR Code Generator - Create QR Codes Free
Free QR Code Generator. Create QR codes for URLs, text, WiFi, email, SMS, vCards. Download as PNG.
PopularQR Code Reader - Decode QR Codes from Image & Camera
Free online QR Code Reader. Decode QR codes from images, screenshots, or live camera. Extract URLs, WiFi passwords, vCards instantly. 100% private browser processing. No signup. AI cannot scan real QR codes - we do.
NewRandom Generator - Number, Dice, Coin, Wheel & Decision Maker
Free online random generator: pick random numbers, roll dice, flip coins, spin a wheel, or make decisions. True randomness via crypto API. No signup, no ads.
Readability Score Calculator Online
Free readability calculator. 6 formulas: Flesch Reading Ease, Flesch-Kincaid, Gunning Fog, SMOG, Coleman-Liau, ARI. Grade level + sentence highlighting.
NewReceipt Generator - Free PDF Receipt Maker Online
Free online receipt generator. Create professional proof-of-payment receipts with unlimited line items, 23 currencies, tax, discount, and PDF download. 3 templates (Simple, Detailed, Business). No signup, no watermark, 100% private browser processing. AI cannot do fixed-precision tax math or format receipts reliably - we do.
NewRegex Tester - Test Regular Expressions
Test regular expressions with real-time matching. Supports g, i, m, s flags. See match count and captured groups.
Report a Problem
Free feedback form for DevTools Hub. Suggest new tools, report bugs, request features. Admin replies via KV storage. No signup.
NewREST API Tester - Free Online HTTP Client & API Tester
Free online REST API tester and HTTP client. Send GET, POST, PUT, PATCH, DELETE requests with custom headers. View real response status, timing, headers, and body. No signup, 100% private. AI cannot make HTTP requests - we do.
NewRoman Numeral Converter - Free Online Number Tool
Free Roman numeral converter. Convert numbers to Roman numerals and back, including dates. Supports 1-3,999,999 with overline notation. 100% accurate, no signup.
NewRunning Pace Calculator - Pace, Time & Distance Tool
Free running pace calculator. Calculate pace, time, or distance for any race. Generate split times, predict race times with Riegel formula, convert pace units. No signup, 100% private browser tool. AI cannot calculate running paces reliably.
NewSalary Calculator - Free Hourly to Annual Pay Converter
Free salary calculator to convert hourly, annual, monthly, biweekly, and weekly pay instantly. Calculate overtime and unpaid time adjustments. No signup, 100% private browser tool. AI hallucinates salary math - we deliver precise results.
NewSchema Markup Generator - Free JSON-LD Structured Data Tool
Free Schema Markup Generator. Create valid JSON-LD structured data for Article, Product, FAQ, LocalBusiness, Organization, HowTo, Event, Person, BreadcrumbList, and WebSite. Built-in validation, live preview, @graph mode. No signup, 100% private browser processing. AI cannot generate valid schema markup - we do.
NewSignature Maker - Sign PDF Online Free
Create a signature by drawing, typing, or uploading a photo, then place it on any PDF and download. Free, private, no watermark.
NewSIP Calculator - Free Mutual Fund Return Calculator
Free SIP calculator. Estimate mutual fund maturity from monthly investment, return and tenure. Goal, step-up and lumpsum modes. 100% private, no signup.
NewSleep Calculator - Bedtime & Wake Up Time Optimizer
Free sleep calculator based on 90-minute cycles. Find your optimal bedtime or wake-up time to feel refreshed. Age-adjusted recommendations for children, teens, adults, and seniors. No signup, 100% private. AI cannot calculate personalized sleep cycles - we use deterministic cycle math.
NewSlug Generator - Create SEO-Friendly URL Slugs Online
Free slug generator. Convert text to SEO-friendly URL slugs with custom separators, stop word removal, max length control, and bulk mode. Real-time preview, 100% private browser, no signup. AI hallucinates slug generation - we use deterministic regex.
NewSnake Game - Classic Snake Online Free
Play the classic Snake game online free. Control your snake, eat food, grow longer. Multiple speeds, grid sizes, wall wrap mode. No ads, no signup.
Solitaire - Free Classic Klondike Card Game Online
Play free Klondike Solitaire online. Classic card game with undo, hint, draw 1 or 3. No signup, no ads, 100% free in your browser.
Song Lyrics Finder - Free Lyrics Search No Signup
Free online song lyrics finder. Search by artist and title. No signup, no ads, no tracking. 100% private. AI cannot retrieve copyrighted lyrics - we do.
NewSpace Keeper - Keep HuggingFace Spaces Awake
Free tool to keep your HuggingFace Spaces awake and prevent idle timeout. Supports multiple access methods, uptime monitor, custom intervals (1-48 hours).
Frequently Asked Questions
Are all 245 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?
No. 245 out of 245 tools process everything in your browser. Only 3 tools (AI Chat, AI Detector, Image Generator, Story Animator) call a server API because the underlying model requires GPU compute — and those calls send no logs.
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 245 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.