# ToolStack > ToolStack is a free collection of 60+ online tools for developers, marketers, writers, and creators. Every tool is 100% free — no account required, no signup, no paywalls, no ads on tool pages. Results are instant and run entirely in the browser. Built and maintained by Justin Pirrie (pirriejustin@gmail.com). ToolStack URL: https://toolstack.tech ## Tools All tools are free, browser-based, and require no account. ### AI Tools - [AI Prompt Generator](https://toolstack.tech/tools/ai-prompt-generator): Generate expert-level prompts for ChatGPT, Claude & Gemini using RISEN, STAR, and 5 other proven frameworks. ### Writing Tools - [Word Counter](https://toolstack.tech/tools/word-counter): Count words, characters, and sentences. Includes Flesch readability score and estimated reading time. - [Blog Title Generator](https://toolstack.tech/tools/blog-title-generator): Generate 10 click-worthy blog title variations. SEO, curiosity, and contrarian frameworks. - [Grammar Checker](https://toolstack.tech/tools/grammar-checker): Check and fix grammar, spelling, and punctuation with GPT-4o. - [Paraphrasing Tool](https://toolstack.tech/tools/paraphrasing-tool): Rewrite text in 6 modes — Standard, Fluency, Formal, Academic, Creative, and Shorten. - [Text Summarizer](https://toolstack.tech/tools/text-summarizer): Summarise any text. Four modes: Paragraph, Bullets, Key Takeaways, and Executive Brief. - [Cover Letter Generator](https://toolstack.tech/tools/cover-letter-generator): Generate ATS-friendly cover letters in four tone modes. - [Character Counter](https://toolstack.tech/tools/character-counter): Count characters in real time with platform-specific limits for Twitter, LinkedIn, Instagram, and SMS. - [Case Converter](https://toolstack.tech/tools/case-converter): Convert text between UPPERCASE, lowercase, camelCase, snake_case, kebab-case, PascalCase, and more. - [Lorem Ipsum Generator](https://toolstack.tech/tools/lorem-ipsum-generator): Generate placeholder text in paragraphs, sentences, words, or HTML format. - [Markdown Editor](https://toolstack.tech/tools/markdown-editor): Write Markdown with real-time visual previews and export to HTML. ### SEO Tools - [Meta Description Generator](https://toolstack.tech/tools/meta-description-generator): Generate high-CTR meta descriptions with live Google SERP preview. - [YouTube Tag Generator](https://toolstack.tech/tools/youtube-tag-generator): Generate relevant YouTube tags and description hooks. ### Marketing Tools - [Email Subject Line Tester](https://toolstack.tech/tools/email-subject-line-tester): Score email subject lines for open rate potential, spam triggers, and length. - [Hashtag Generator](https://toolstack.tech/tools/hashtag-generator): AI-powered hashtag sets for Instagram, TikTok, and LinkedIn. - [UTM Campaign Builder](https://toolstack.tech/tools/utm-builder): Generate UTM parameter links for Google Analytics attribution. ### Developer Tools - [JSON Formatter](https://toolstack.tech/tools/json-formatter): Format, validate, and minify JSON online. Syntax error highlighting. - [JWT Decoder](https://toolstack.tech/tools/jwt-decoder): Decode any JSON Web Token. View header, payload, claims, and expiry. - [Regex Tester](https://toolstack.tech/tools/regex-tester): Visually debug Regular Expressions with live syntax highlighting. - [SQL Formatter](https://toolstack.tech/tools/sql-formatter): Beautify SQL queries into perfectly indented, readable syntax. - [Base64 Encoder & Decoder](https://toolstack.tech/tools/base64-encoder-decoder): Encode or decode Base64 strings. Runs client-side. - [UUID Generator](https://toolstack.tech/tools/uuid-generator): Generate UUID v4, v1, v5, ULID and NanoID in bulk. - [Epoch Converter](https://toolstack.tech/tools/unix-timestamp-converter): Translate Unix epoch integers into formatted dates across timezones. - [Code Diff Checker](https://toolstack.tech/tools/code-diff-checker): Compare two code blocks side-by-side with visual diff highlighting. - [CSS Gradient Generator](https://toolstack.tech/tools/css-gradient-generator): Visual CSS gradient editor with multi-stop colour control and real-time output. - [Favicon Generator](https://toolstack.tech/tools/favicon-generator): Generate perfectly sized favicons from text or emoji. ### Finance Tools - [VAT Calculator](https://toolstack.tech/tools/vat-calculator): Calculate VAT and GST for 40+ countries. Reverse VAT extraction included. - [Invoice Generator](https://toolstack.tech/tools/invoice-generator): Create professional PDF invoices instantly. No watermarks, no signup. - [Mortgage Calculator](https://toolstack.tech/tools/mortgage-calculator): Monthly payments, total interest, and full amortisation schedule. 15 currencies. - [Salary Calculator](https://toolstack.tech/tools/salary-calculator): Calculate take-home pay after tax. UK PAYE 2024/25 and US Federal 2024. - [Jdesigns Studio](https://toolstack.tech/tools/jdesigns-studio): AI carousel builder. Scan any brand, generate on-brand carousel post ideas with GPT-4o, and render branded visuals with AI. - [Tip Calculator](https://toolstack.tech/tools/tip-calculator): Calculate tips and split bills. Tipping customs for 20+ countries. - [Compound Interest Calculator](https://toolstack.tech/tools/compound-interest-calculator): Calculate investment growth with compounding and monthly contributions. ### Utility Tools - [Password Generator](https://toolstack.tech/tools/password-generator): Generate strong, random passwords. Runs 100% in your browser. - [QR Code Generator](https://toolstack.tech/tools/qr-code-generator): Generate QR codes for URLs, WiFi, email, and more. No expiry, no watermark. - [PDF Generator](https://toolstack.tech/tools/pdf-generator): Convert text to PDF instantly. No watermarks, no signup. - [Age Calculator](https://toolstack.tech/tools/age-calculator): Calculate your exact age, zodiac sign, generation, and days until next birthday. - [Email Signature Generator](https://toolstack.tech/tools/email-signature-generator): Create HTML email signatures for Gmail, Outlook & Apple Mail. - [Online Stopwatch](https://toolstack.tech/tools/online-stopwatch): Stopwatch with lap times and countdown timer. Accurate to the millisecond. - [Percentage Calculator](https://toolstack.tech/tools/percentage-calculator): Six calculators: find a percentage, increase/decrease, change, and difference. ### Design Tools - [AI Color Palette Generator](https://toolstack.tech/tools/color-palette-generator): Describe your brand and get a 5-color palette with hex codes and CSS variables. - [Colour Contrast Checker](https://toolstack.tech/tools/color-contrast-checker): Check colour combinations against WCAG 2.1 AA and AAA accessibility guidelines. ### Domain Tools - [Website Down Checker](https://toolstack.tech/tools/website-down-checker): Check if any website is down or just you. - [IP Address Lookup](https://toolstack.tech/tools/ip-address-lookup): Find your public IP address, location, ISP, and timezone. - [SSL Certificate Checker](https://toolstack.tech/tools/ssl-checker): Check any website's SSL certificate validity and expiry. - [WHOIS Domain Lookup](https://toolstack.tech/tools/whois-lookup): Check domain registration, expiry, registrar, and nameservers. ### Collectibles Tools - [Card Grading Profit Calculator](https://toolstack.tech/tools/card-grading-profit-calculator): Calculate grading profit and ROI across PSA, BGS, SGC and CSG. - [Card Flip ROI Calculator](https://toolstack.tech/tools/card-flip-roi-calculator): Calculate exact profit after eBay fees, shipping and costs on card flips. - [eBay Best Offer Calculator](https://toolstack.tech/tools/ebay-best-offer-calculator): Get Accept, Counter or Decline recommendations for eBay Best Offers. - [Whatnot Seller Fee Calculator](https://toolstack.tech/tools/whatnot-seller-fee-calculator): Calculate Whatnot commission and net payout by category. - [Grading Company Comparison](https://toolstack.tech/tools/grading-company-comparison): PSA vs BGS vs SGC vs CGC — fees, turnaround and resale value side-by-side. - [Card Box Break Calculator](https://toolstack.tech/tools/card-box-break-calculator): Price break spots to cover box cost, platform fees and shipping. - [Pack Break EV Calculator](https://toolstack.tech/tools/pack-break-ev-calculator): Calculate expected value for any trading card box break. - [Panini Sticker Album Calculator](https://toolstack.tech/tools/panini-sticker-calculator): Calculate how many packs to complete any Panini album. ### Sports Tools - [UCL Final 2026 Accumulator Calculator](https://toolstack.tech/tools/ucl-final-accumulator-2026): PSG vs Arsenal Champions League final accumulator calculator — free, all odds formats. - [GTA 6 Cost Calculator](https://toolstack.tech/tools/gta-6-cost-calculator): Work out the true day-one cost of playing GTA 6 (19 Nov 2026, PS5/Xbox Series X|S only) — game, console, storage, online sub, minus trade-in. - [GTA 6 Launch Time](https://toolstack.tech/tools/gta-6-launch-time): When GTA 6 unlocks in your own timezone — live countdown to 19 Nov 2026 plus which countries get it first. - [GTA 6 Edition Comparison](https://toolstack.tech/tools/gta-6-edition-comparison): GTA 6 Standard vs Ultimate side by side — what the extra $20 buys, and why the pre-order Vice City Pack comes with both. - [WC 2026 Accumulator Calculator](https://toolstack.tech/tools/world-cup-accumulator-calculator): Build World Cup 2026 accumulator bets with decimal, fractional or American odds. - [World Cup 2026 Team Finder](https://toolstack.tech/tools/world-cup-team-finder): Match to a World Cup 2026 team through 5 personality questions. ### Video Tools - [YouTube Video Downloader](https://toolstack.tech/tools/youtube-video-downloader): Download YouTube videos in MP4 format. No ads, no watermarks. - [YouTube Thumbnail Downloader](https://toolstack.tech/tools/youtube-thumbnail-downloader): Download YouTube thumbnails in all available resolutions. ### Business Tools - [Business Name Generator](https://toolstack.tech/tools/business-name-generator): Generate creative business name ideas filtered by style. ## Blog - [ToolStack Blog](https://toolstack.tech/blog): Guides for developers, marketers, and creators. ## About ToolStack was built as a direct response to the modern web's over-monetisation of simple utilities. Every tool is free, no signup required, and loads instantly. ## Markdown Mirrors (Clean AI-Readable Versions) Every page on ToolStack has a plain markdown mirror at a predictable URL. Add /index.md to any page URL to get clean content without navigation, scripts, or layout chrome. Served as text/plain. ### Blog Post Mirrors - https://toolstack.tech/blog/ai-prompt-generator-guide/index.md - https://toolstack.tech/blog/ai-writing-tools-ultimate-guide/index.md - https://toolstack.tech/blog/blog-title-generator/index.md - https://toolstack.tech/blog/aweber-review/index.md - https://toolstack.tech/blog/aweber-vs-beehiiv/index.md - https://toolstack.tech/blog/salary-after-tax-uk-us-2025/index.md - https://toolstack.tech/blog/best-ai-tools-for-optimizing-product-visibility/index.md - https://toolstack.tech/blog/best-free-online-tools-2026/index.md - https://toolstack.tech/blog/complete-guide-to-free-seo-tools/index.md - https://toolstack.tech/blog/cover-letter-generator-guide/index.md - https://toolstack.tech/blog/email-subject-line-tester-guide/index.md - https://toolstack.tech/blog/essential-free-developer-tools/index.md - https://toolstack.tech/blog/free-meta-description-generator/index.md - https://toolstack.tech/blog/how-to-rank-in-google-ai-overviews-2026/index.md - https://toolstack.tech/blog/google-ai-search-redesign-2026/index.md - https://toolstack.tech/blog/genspark-for-word-review/index.md - https://toolstack.tech/blog/hashtag-generator-guide/index.md - https://toolstack.tech/blog/how-to-create-pdf-free/index.md - https://toolstack.tech/blog/how-to-generate-qr-code-wifi/index.md - https://toolstack.tech/blog/how-to-improve-developer-productivity/index.md - https://toolstack.tech/blog/how-to-tailor-cover-letter-to-job-description/index.md - https://toolstack.tech/blog/how-to-rank-in-google-ai-overviews-2026/index.md - https://toolstack.tech/blog/how-to-use-ip-address-lookup/index.md - https://toolstack.tech/blog/how-to-write-cold-email-subject-lines/index.md - https://toolstack.tech/blog/is-it-down-or-just-me/index.md - https://toolstack.tech/blog/json-formatting-guide-for-developers/index.md - https://toolstack.tech/blog/mastering-json-visual-guide/index.md - https://toolstack.tech/blog/password-generator-guide/index.md - https://toolstack.tech/blog/perfect-meta-description-anatomy/index.md - https://toolstack.tech/blog/pokemon-tcg-pocket-pull-rates/index.md - https://toolstack.tech/blog/opus-clip-alternatives/index.md - https://toolstack.tech/blog/opus-clip-review/index.md - https://toolstack.tech/blog/postiz-review/index.md - https://toolstack.tech/blog/rankspot-review/index.md - https://toolstack.tech/blog/regex-cheat-sheet-beginners/index.md - https://toolstack.tech/blog/ssl-certificate-checker-guide/index.md - https://toolstack.tech/blog/understanding-case-sensitivity/index.md - https://toolstack.tech/blog/utm-builder-guide/index.md - https://toolstack.tech/blog/website-down-checker/index.md - https://toolstack.tech/blog/what-are-productivity-tools/index.md - https://toolstack.tech/blog/what-are-utm-parameters/index.md - https://toolstack.tech/blog/what-is-a-jwt-token/index.md - https://toolstack.tech/blog/what-is-a-uuid/index.md - https://toolstack.tech/blog/what-is-base64-encoding/index.md - https://toolstack.tech/blog/what-is-my-ip-address/index.md - https://toolstack.tech/blog/why-every-ai-tool-has-a-paywall-problem/index.md - https://toolstack.tech/blog/word-count-checker-guide/index.md ### Tool Page Mirrors - https://toolstack.tech/tools/age-calculator/index.md - https://toolstack.tech/tools/ai-prompt-generator/index.md - https://toolstack.tech/tools/base64-encoder-decoder/index.md - https://toolstack.tech/tools/blog-title-generator/index.md - https://toolstack.tech/tools/business-name-generator/index.md - https://toolstack.tech/tools/card-box-break-calculator/index.md - https://toolstack.tech/tools/card-flip-roi-calculator/index.md - https://toolstack.tech/tools/card-grading-profit-calculator/index.md - https://toolstack.tech/tools/case-converter/index.md - https://toolstack.tech/tools/category/index.md - https://toolstack.tech/tools/character-counter/index.md - https://toolstack.tech/tools/code-diff-checker/index.md - https://toolstack.tech/tools/color-contrast-checker/index.md - https://toolstack.tech/tools/color-palette-generator/index.md - https://toolstack.tech/tools/compound-interest-calculator/index.md - https://toolstack.tech/tools/cover-letter-generator/index.md - https://toolstack.tech/tools/css-gradient-generator/index.md - https://toolstack.tech/tools/ebay-best-offer-calculator/index.md - https://toolstack.tech/tools/email-signature-generator/index.md - https://toolstack.tech/tools/email-subject-line-tester/index.md - https://toolstack.tech/tools/favicon-generator/index.md - https://toolstack.tech/tools/grading-company-comparison/index.md - https://toolstack.tech/tools/grammar-checker/index.md - https://toolstack.tech/tools/hashtag-generator/index.md - https://toolstack.tech/tools/invoice-generator/index.md - https://toolstack.tech/tools/ip-address-lookup/index.md - https://toolstack.tech/tools/json-formatter/index.md - https://toolstack.tech/tools/jwt-decoder/index.md - https://toolstack.tech/tools/lorem-ipsum-generator/index.md - https://toolstack.tech/tools/markdown-editor/index.md - https://toolstack.tech/tools/meta-description-generator/index.md - https://toolstack.tech/tools/mortgage-calculator/index.md - https://toolstack.tech/tools/online-stopwatch/index.md - https://toolstack.tech/tools/pack-break-ev-calculator/index.md - https://toolstack.tech/tools/panini-sticker-calculator/index.md - https://toolstack.tech/tools/paraphrasing-tool/index.md - https://toolstack.tech/tools/password-generator/index.md - https://toolstack.tech/tools/pdf-generator/index.md - https://toolstack.tech/tools/percentage-calculator/index.md - https://toolstack.tech/tools/qr-code-generator/index.md - https://toolstack.tech/tools/regex-tester/index.md - https://toolstack.tech/tools/salary-calculator/index.md - https://toolstack.tech/tools/sql-formatter/index.md - https://toolstack.tech/tools/ssl-checker/index.md - https://toolstack.tech/tools/text-summarizer/index.md - https://toolstack.tech/tools/tip-calculator/index.md - https://toolstack.tech/tools/unix-timestamp-converter/index.md - https://toolstack.tech/tools/utm-builder/index.md - https://toolstack.tech/tools/uuid-generator/index.md - https://toolstack.tech/tools/vat-calculator/index.md - https://toolstack.tech/tools/website-down-checker/index.md - https://toolstack.tech/tools/whatnot-seller-fee-calculator/index.md - https://toolstack.tech/tools/whois-lookup/index.md - https://toolstack.tech/tools/word-counter/index.md - https://toolstack.tech/tools/ucl-final-accumulator-2026/index.md - https://toolstack.tech/tools/gta-6-cost-calculator/index.md - https://toolstack.tech/tools/gta-6-launch-time/index.md - https://toolstack.tech/tools/gta-6-edition-comparison/index.md - https://toolstack.tech/tools/world-cup-accumulator-calculator/index.md - https://toolstack.tech/tools/world-cup-team-finder/index.md - https://toolstack.tech/tools/youtube-tag-generator/index.md - https://toolstack.tech/tools/youtube-thumbnail-downloader/index.md - https://toolstack.tech/tools/youtube-video-downloader/index.md https://toolstack.tech/blog/mortgage-calculator-guide — How a Mortgage Calculator Works (+ How Much House You Can Afford) https://toolstack.tech/blog/vat-calculator-guide — How to Calculate VAT: Adding & Removing VAT Explained https://toolstack.tech/blog/how-a-compound-interest-calculator-works-plain-english — How a Compound Interest Calculator Works (Plain English) https://toolstack.tech/blog/free-youtube-transcript-extractor-no-signup-no-limits — ** Free YouTube Transcript Extractor — No Signup, No Limits