Developer tools that work.
323 free utilities for code formatting, file conversion, calculations, 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 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.
Free 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.
NewImage 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 Free Online with Aspect Ratio Presets
Free online image cropper. Crop photos with aspect ratio presets, rotate, flip, zoom. Social media sizes for Instagram, Facebook, Twitter. No upload, 100% private browser processing. AI cannot crop your photos - we do.
NewJSON Formatter - Format & Validate JSON
Free JSON formatter. Format, minify, beautify JSON and convert to YAML with syntax error detection.
JSON to CSV Converter - Bidirectional Online Data Converter
Free JSON to CSV converter and CSV to JSON online. Flatten nested objects, auto-detect input, table preview, export file. 100% private browser processing. AI cannot convert data reliably - we do.
NewLive Sports Scores Tracker - NFL NBA MLB NHL Soccer
Free live sports scores tracker. Follow NFL, NBA, MLB, NHL and soccer in real-time. Updated every 30 seconds. No signup, no ads. AI cannot show live game scores - we do.
NewRecently Updated
6 toolsAPCA Contrast Checker - WCAG 3 Lc Calculator
Free APCA contrast checker for WCAG 3. Get the Lc value, the minimum Lc your font size and weight need, the WCAG 2.1 ratio, and a passing color fix.
NewPDF Compare - Free Online PDF Diff & Side-by-Side
Free PDF compare tool. Side-by-side visual diff with scroll sync, text-based diff with green/red highlights, page-by-page navigation, export PDF report. 100% private browser processing, no upload, no signup.
NewMath Calculator - Polynomial, Matrix, Prime Factor & More
Free math calculator. 6 modes: polynomial factoring, prime factorization, GCF/LCM, matrix (det/inv), quadratic formula, sequence. Step-by-step. No signup.
NewFree OG Image Generator - Social Card Creator 1200x630
Free OG image generator. 1200x630 Open Graph cards with multi-platform preview (Twitter, Facebook, LinkedIn, Slack). 6 templates, custom colors, fonts, logo upload. Download PNG and copy meta tags. No signup, 100% browser. AI cannot output exact OG dimensions + multi-platform safe area validation.
NewTDEE Calculator - BMR, Macro, Protein, Water, 1RM
Free TDEE calculator. 6 modes in one: BMR (3 formulas), macro split (5 diets), protein target, water intake, and 1 rep max. kg/lb toggle. No signup.
NewAI Essay Writer - Free Academic Essay Generator
Free AI essay writer for 9 types, 4 levels, 5 citation styles. Outline + thesis + draft modes, editable, downloadable. No signup, no word limit.
NewBrowse by Category
11 categoriesView all 323 tools (alphabetical)
HTML Entity Encoder/Decoder - Encode & Decode Special…
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. Format, prettify and beautify HTML code with proper indentation and validation.
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 & IBAN Checker - Validate IBAN Numbers Online
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 Free Online with Aspect Ratio Presets
Free online image cropper. Crop photos with aspect ratio presets, rotate, flip, zoom. Social media sizes for Instagram, Facebook, Twitter. No upload, 100% private browser processing. AI cannot crop your photos - we do.
NewImage Enhancer - Free Photo Quality Booster
Free image enhancer. Adjust brightness, contrast, saturation, vibrance, sharpness, denoise, HDR, color temp in real-time. 9 pro filters + 1-click Auto Enhance. 100% browser, no upload, no signup, no watermark.
NewImage 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, 12+…
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.
NewImage 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
Free image upscaler to 2x, 3x, 4x. Edge-aware sharpening, denoise, browser-based. No upload, no signup, 100% private.
NewImage Vectorizer - Free PNG JPG to SVG Converter Online
Free image vectorizer. Convert PNG, JPG, WebP, BMP, GIF to scalable SVG vectors in your browser. 9 presets, color count, blur, threshold, path tolerance controls. 100% private, no upload, no signup. AI cannot vectorize - we do.
NewImage Watermark - Add Text & Logo Watermark to Photos Free…
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 - Stock Profit & 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
Free IP address lookup tool. Find your public IP, location, ISP, and geolocation data instantly. No signup required.
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.
JavaScript Obfuscator - Protect JS Code Online
Free online JavaScript obfuscator. Protect your JS code with variable renaming, string encryption, control flow flattening, and more. 100% private browser…
JS Formatter & Beautifier - JavaScript Code Beautify Online
Free online JavaScript formatter and beautifier. Beautify messy JS, minify for production, validate syntax. No signup, 100% private browser processing.
JSON Diff - Compare & Find Differences Between Two JSON…
Free JSON diff tool. Compare two JSON documents and see differences instantly. Highlights added, removed, and modified values. Side-by-side view with…
JSON Formatter - Format & Validate JSON
Free JSON formatter. Format, minify, beautify JSON and convert to YAML with syntax error detection.
PopularJSON Schema Validator - Validate JSON Against Schema Online
Free online JSON Schema validator. Validate JSON data against Draft-07, 2019-09, and 2020-12 schemas. Detailed error paths, all-errors mode. No signup, no…
JSON to CSV Converter - Bidirectional Online Data Converter
Free JSON to CSV converter and CSV to JSON online. Flatten nested objects, auto-detect input, table preview, export file. 100% private browser processing. AI cannot convert data reliably - we do.
NewJSON to TypeScript Converter - Free Interface & Zod…
Free JSON to TypeScript converter. Generate TypeScript interfaces, types, and Zod schemas from JSON. Deterministic output, no hallucination. 100% private…
JSON to XML Converter - Free Bidirectional Online Tool
Free JSON to XML converter and XML to JSON. Bidirectional with attribute handling, root element control, indentation options, syntax validation. 100%…
JSON to YAML Converter - Free Online Tool
Free JSON to YAML converter and YAML to JSON. Bidirectional with indentation control, key sorting, and syntax validation. 100% private, no upload.
JWT Decoder - Decode & Verify Tokens
Free JWT decoder. Decode tokens, inspect claims, verify signatures in your browser.
JWT Generator - Create Signed Tokens Online
Free JWT generator. Create signed JSON Web Tokens with HS256, HS384, HS512 algorithms. No signup, no upload, 100% private browser processing.
Keyboard Tester - Test All Keys Online Free
Free online keyboard tester. Press every key to check if it works. Detect stuck keys, ghosting, and rollover. Multiple layouts, test report, no signup.
Live Sports Scores Tracker - NFL NBA MLB NHL Soccer
Free live sports scores tracker. Follow NFL, NBA, MLB, NHL and soccer in real-time. Updated every 30 seconds. No signup, no ads. AI cannot show live game scores - we do.
NewLoan Calculator - Mortgage & Extra Payment Optimizer
Free loan calculator that shows more than just your payment. See how extra payments save thousands, when PMI drops, and when you own your home free.
Lorem Ipsum Generator - Free Placeholder Text
Free Lorem Ipsum generator. Generate placeholder text by paragraphs, sentences, or words. Classic or randomized. No signup.
Margin Calculator - Free Profit Markup Tool
Free margin calculator. Bidirectional margin to markup, profit margin, selling price with tax layer, break-even units, multi-product. 100% private.
Math Calculator - Polynomial, Matrix, Prime Factor & More
Free math calculator. 6 modes: polynomial factoring, prime factorization, GCF/LCM, matrix (det/inv), quadratic formula, sequence. Step-by-step. No signup.
NewMermaid Diagram Generator - Free Flowchart & Diagram…
Free online Mermaid diagram generator. Create flowcharts, sequence diagrams, class diagrams, ER diagrams, Gantt charts from text. Live preview, SVG/PNG…
Meta Tag Generator - Free SEO Tool
Free SEO meta tag generator. Create title tags, meta descriptions, OG, and Twitter Cards with live SERP preview. Character counting, copy HTML. No signup.
NewMicrophone Test - Free Online Mic Tester
Free online microphone test. Measure mic levels, detect clipping and noise, play back your voice, get a verdict and report. No signup, 100% private.
Mileage Calculator - IRS Tax Deduction Tracker Free
Free mileage calculator with IRS tax deduction tracker. Auto-handles 2026 mid-year rate. Business, medical, moving, charity. CSV export, 100% private.
Mock 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, and more. No signup,…
Monitor Test - Dead Pixel & Refresh Rate Tester Online
Free online monitor test. Detect dead pixels, stuck pixels, backlight bleed, banding and ghosting. Measure your real refresh rate with full-screen…
Frequently Asked Questions
Are all 323 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 323 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.