Thinker Toolbox is a collection of free, browser-based utilities that actually work. No sign-ups, no subscriptions, no data harvesting. Just tools that do what they say on the tin.
We got fed up with word puzzle solvers that are buried under clutter, colour pickers that want your email, and tip calculators that track your dinner bills. So we built our own. Then we put them all in one place, made them work offline, and called it Thinker Toolbox.
The name used to be a bit misleading — but we reckon Thinker Toolbox covers it. We've got word puzzles, financial calculators, a colour picker, a Sudoku solver, a tip calculator, and a cooking converter. Tools for thinkers, all in one toolbox.
Crossword Solver
Stuck on a crossword? Type in your pattern with ? for unknown letters and we'll find all matching words.
Anagram Solver
Got a jumble of letters? Find every word that can be made from them, sorted by length and Scrabble score.
Wordle Solver
Enter your guesses and the green/yellow/grey feedback. We'll narrow down the possibilities and suggest your best next guess.
Scrabble Word Finder
Enter your rack letters and any board letters. We'll find every valid word, sorted by Scrabble score. Bingo words get a ⭐.
Mortgage Calculator
Calculate monthly payments, view amortization schedules, see how overpayments save you money, compare mortgage deals, check stamp duty, and find out how much you could borrow.
Percentage Calculator
Work out percentages of numbers, percentage increases and decreases, reverse percentages (remove VAT), and more. Live calculation as you type.
Savings Calculator
See how your savings grow with compound interest. Plan regular contributions, set savings goals, and view growth charts showing contributions vs interest earned.
Colour Picker
Pick a colour and instantly see complementary, triadic, analogous, and other harmonious palettes. Includes WCAG contrast checking and — snap a photo to extract dominant colours.
Sudoku Solver
Stuck on a Sudoku? Enter the puzzle and get the solution instantly. Or use hint mode to reveal just one cell at a time.
Tip Calculator
Quick tip calculation with presets (15%, 18%, 20%, 25%) and bill splitting between friends. Round up or split exactly.
Cooking Converter
Convert cups to grams (with ingredient-specific densities — a cup of flour ≠ a cup of sugar), scale recipes, and look up common conversions.
Works offline. Once you've visited, the tools cache themselves in your browser. No internet? No problem. On the train, in a café, in a dead zone — they still work.
Works on your phone. Every tool is designed mobile-first. Big buttons, readable text, no pinching and zooming.
Fast. No server round-trips for calculations. Everything runs in your browser. The word puzzles load a 168,000-word dictionary instantly.
Private. We use Google AdSense which may set cookies for personalised ads. You can accept or reject these in the cookie banner. Your calculator inputs stay in your browser and are never sent anywhere.
No accounts. No sign-up, no email, no password. Just open and use.
The calculators on this site are for illustration purposes only and do not constitute financial advice.
Mortgage payments, savings projections, and other financial calculations are estimates based on the figures you provide. Actual amounts may vary depending on your lender's terms, interest rate changes, fees, and other factors not captured by these tools.
Always consult a qualified financial adviser before making important financial decisions. Do not rely solely on these calculators when considering mortgages, loans, savings, or investments.
The dictionary used in the word puzzle tools is the ENABLE word list (Public Domain), containing over 168,000 Scrabble-valid words. It also includes the official Wordle answer list for the Wordle Solver.
It's great for casual use, but if you're training for competitive Scrabble, you should note that a small number of words added in later Scrabble dictionary updates (such as QI and ZA) are not included in the ENABLE list.
Made with ♥ by a ragtag bunch who got tired of tools that don't just work.
Got feedback, found a bug, or got an idea for a new tool? We'd love to hear from you.
🍪 We use Google AdSense which may set cookies for personalised ads. You can accept or reject personalised advertising.