All Online Tools

Work out how many calories you need per day from your age, gender, height, weight and activity level. See your BMR, your TDEE and calorie targets for losing or gaining weight — all based on the Mifflin-St Jeor equation.

Build a .gitignore file for your stack. Pick from 30+ templates covering languages, frameworks, editors, IDEs and operating systems, or choose a quick preset for Web, Mobile, Backend or Data/ML. Add custom patterns and download the file.

Create QR codes for URLs, plain text, email, phone, SMS, Wi-Fi and vCard. Tune size, margin, error correction level and colors. Download as PNG for digital use or as SVG for print. Also supports ten barcode formats including CODE128, EAN and UPC.

Find the final price after a discount and see exactly how much you save. Optionally add sales tax — applied to the discounted price, the way it works at checkout. Works for any store, any currency.

Estimate your VO2 max — the best single measure of aerobic fitness — using the Rockport 1-mile walk test. Walk a mile as fast as you can, record your time and heart rate, and see how you compare to age and gender norms.

Give the generator a few example strings that should match — and optionally some that should not — and get a working regular expression. It analyses the common structure, produces a pattern with a plain-English explanation and validates the result against your negative examples.

Measure the return on any investment or project. Two modes: enter an initial and final amount for a simple ROI, or enter revenue and cost for a business return. See the profit, margin and ROI percentage together.

Compute MD5, SHA-1, SHA-256 and SHA-512 hashes for any text — all four at once. SHA algorithms use the browser's native Web Crypto API; MD5 runs through a local implementation. Everything happens on your device.

Convert between units of length, weight, temperature, area, volume, speed, time, data, pressure and energy. Enter a value once and see it converted to every other unit in the same category, or swap the direction with one click.

Encode or decode URLs and query parameters. Two modes: Component encodes everything including ?, & and = (use it for query values), Full URL preserves reserved characters (use it for complete URLs). Result updates as you type.

Estimate your ideal body weight using four classic formulas — Devine, Robinson, Miller and Hamwi — and see the average. Enter your height and gender to get all four results side by side, plus the clinical reference used in medical settings.

Find your exact age in years, months and days from your birth date. Enter any target date — today, a past date or a future one — and see how many days and weeks you have been alive. Handles February 29 birthdays correctly.

Work out your Total Daily Energy Expenditure and the protein, carb and fat targets that match your goal. Choose lose, maintain or gain — the calculator adjusts both calories and macro split. Uses the Mifflin-St Jeor equation.

Check whether your text and background colors pass WCAG 2.1 AA and AAA. See the contrast ratio, live preview at three text sizes and pass/fail status for normal text, large text and UI components. Swap foreground and background with one click.

Predict your next period, ovulation date and fertile window from your last period and average cycle length. See your next three period dates and the current day of your cycle. Based on the standard luteal-phase method used by cycle trackers.

Count words, characters (with and without spaces), sentences, paragraphs and pages as you type. See estimated reading and speaking time, plus live counters for Twitter, Instagram, LinkedIn, YouTube and meta description limits.

Generate cryptographically secure UUIDs — up to 100 per click. Choose version 4 (fully random) or version 7 (time-ordered, sortable by creation time). Toggle uppercase or lowercase, with or without dashes. Copy results with one click.

Build a full set of meta tags with live previews of how the page will look in Google search and when shared on social media. Fill in title, description, URL, social image, site name, Twitter handle and OG type — copy the whole block and paste it into your head section.

Calculate the maturity value and interest earned on a fixed deposit or term deposit. Choose any compounding frequency — monthly, quarterly, semiannually, annually or daily — and see the effective annual rate.

Convert any number into words. See the number spelled out in English, with Russian added alongside if your browser language is Russian. Handles negatives and integers from −1 trillion to 1 trillion, with correct grammatical forms.

Create professional invoices in your browser and download them as PDF. Two templates (Modern and Classic), five theme colors, logo upload, discounts and tax. Everything autosaves to your device — no account, no uploads, no watermark.

Combine JPG, PNG, WebP, AVIF and GIF images into a single PDF. Choose page size and orientation, put 1 to 3 images per row, set margins and gaps, add page numbers, captions or a title page. Reorder and rotate images before export. Everything happens in your browser.

Generate placeholder text by paragraphs, sentences or words. Optionally start with the classic "Lorem ipsum dolor sit amet" opening and wrap each paragraph in HTML tags for direct paste into templates. Copy the whole result in one click.

Add a text watermark, a logo, or both — right in your browser. Control position, opacity, rotation, font size, color and logo size. Choose from ten anchor positions plus a tile mode that repeats the mark across the whole image. Works on a single image or a whole batch.

Pick a color and see it in HEX, RGB, HSL and HSV — all four formats at once. Generate complementary, analogous, triadic, split-complementary and monochromatic palettes. See tints and shades of the current color. Click any swatch to copy it.

Create professional quotations and estimates in your browser. Fill in company and client details, add line items with quantity and rate, apply discount and tax, set a validity date — then save as PDF or print. Autosaves locally. No account, no watermark.

Paste a JWT and see its header, payload, signature and expiry decoded in one view. Checks whether the token is still valid or has expired. Runs entirely in your browser — nothing is logged, stored or sent anywhere.

Add tax to a net price or extract it from a gross price — works for sales tax, VAT and GST at any rate. See the net, tax and gross amounts side by side so you can verify the calculation instantly.

Find out how much water you actually need each day — not a generic 8 glasses, but a target based on your body weight, daily exercise and climate. See the result in litres and in 250 ml glasses so it is easy to track.

See the maximum loan you can qualify for based on income, existing debts and the lender's debt-to-income limit. Enter monthly income and current payments to get your borrowing ceiling and available monthly payment.

Encode text to Base64 or decode Base64 back to plain text. Switch between Standard (+ and /) and URL-safe (- and _) alphabets depending on where the output will go. Result appears as you type — no button to press.

Work out the best time to go to bed based on when you need to wake up. The calculator aligns your bedtime with full 90-minute sleep cycles, so you finish a cycle in light sleep instead of waking up groggy in the middle of deep sleep.

Find the exact number of days, weeks, months and years between any two dates. Pick the start and end dates — or leave the end empty to use today. Handles past and future dates, including leap years.

Turn SVG markup into a Data URI for CSS backgrounds or inline HTML. Get ready-to-use snippets in four flavours: URL-encoded CSS background, Base64 CSS background, HTML img tag and raw Data URI. Live SVG preview confirms the rendering before you copy.

Build box-shadows and gradients visually. Add multiple shadow layers, each with its own offsets, blur, spread, color and inset toggle. For gradients, choose linear, radial or conic and add as many color stops as you need. Live preview updates as you adjust.

Convert images to WebP, JPEG or PNG — and resize them at the same time. Choose fit, fill or stretch for the target dimensions, adjust quality for JPEG and WebP, and download individually or as a batch. Everything happens in your browser.

Beautify, minify and validate JSON. Invalid input gets flagged with the exact line and column where the syntax breaks. Compare payload sizes before and after minification, then copy the result or download it as a .json file.

Check your Body Mass Index in seconds. Enter your height and weight to see your BMI, your WHO weight category and the healthy weight range for your height. Switch between metric and imperial units.

Generate sequential invoice numbers with a prefix, starting number and leading-zero padding. Attach client names and PO references to each number and keep a local log so you never reuse the same number twice. Everything is stored in your browser.

Work out percentages in seconds — find X% of a number, see what percent one value is of another, reverse a percentage, measure the change between two values, or add and subtract a percent. The result updates live as you type.

Find letters from another alphabet inside your text: Latin inside Cyrillic, Cyrillic inside Latin, Greek symbols, and invisible marks. Pick the alphabet and the tool highlights every match.

Find the point where revenue equals costs. Enter fixed costs, price per unit and variable cost per unit to see break-even volume, break-even revenue and contribution margin. Add expected sales to get your margin of safety.

Write Markdown on the left, see the rendered HTML on the right. Supports GitHub Flavored Markdown — tables, task lists, strikethrough, autolinks and fenced code blocks. All output is sanitized with DOMPurify. Download the rendered HTML as a standalone file.

Project the future value of regular monthly contributions. Enter the amount, expected return and years to see the total invested, the gains earned and what share of the final amount came from returns.

Build trackable campaign URLs with UTM parameters for Google Analytics and Yandex Metrica. Fill in source, medium, campaign and optionally term and content — the tracked URL updates as you type. One click to copy the finished link.

Work out your five training zones from your age and resting heart rate — using either the simple 220 − age formula or the more personalised Karvonen method. See the bpm range for recovery, fat burn, aerobic, threshold and VO2 max.

Create and sign JSON Web Tokens with HS256, HS384 or HS512 — all locally in your browser via the Web Crypto API. Edit the header, add claims to the payload, enter your secret, and copy the signed token. Your secret never leaves your device.

Track your pregnancy week by week. Enter your last period or due date and see your current week, trimester, progress percentage and days until birth. Uses the medical convention of counting from the last menstrual period, not conception.

Split the bill and work out the tip in one step. Enter the bill, choose a tip percentage and set how many people are paying. See the tip amount, the total and exactly what each person owes.

Convert Unix timestamps to ISO, UTC, local and relative time — and back. Choose seconds or milliseconds, use the quick +/- buttons for hours and days, or paste a whole list of timestamps to convert in one batch.

Plan a sustainable weight loss pace. Enter your stats, goal weight and timeframe — the planner returns your daily calorie target and a weekly loss estimate, flagging whether the pace is healthy, too slow or too fast.

Estimate your body fat percentage using the US Navy method — a tape-measure formula trusted by the military and fitness professionals. Enter a few circumference measurements and see your body fat percentage, fat mass and lean mass.

See how much sleep you have accumulated as a deficit over any period. Enter your target and actual sleep, choose how many days the pattern lasted, and get the total debt, severity level and recovery time.

Find out how much you need to save each month to reach a financial goal. Enter the target amount, any starting deposit and the years you have — get the monthly contribution, total invested and expected gains.

Resize dozens of images in one pass. Choose max dimensions, exact pixel size or a percentage scale; pick fit, fill or stretch; and optionally convert format in the same run. See original vs resized size and download all results together.

Generate standard open source licenses — MIT, Apache 2.0, GPL-3.0, AGPL-3.0, LGPL-3.0, BSD-2, BSD-3, ISC, MPL-2.0, Unlicense — with your year, copyright holder and project name filled in. Copy the LICENSE text or download it as a file.

Estimate income tax with custom brackets that work for any country. Enter gross income, deductions, base and higher rates to see total tax, effective rate, marginal rate and take-home pay.

Compare the long-term financial outcome of buying a home versus renting and investing the difference. Enter your numbers and see which option leaves you with more equity or a bigger portfolio after the comparison period.

Convert text between nine case styles: UPPERCASE, lowercase, Title Case, Sentence case, camelCase, PascalCase, snake_case, kebab-case and CONSTANT_CASE. Pick a style and the result updates instantly — one click to copy.

Generate a professional payslip or salary slip in your browser. Add custom earnings and deductions, and the gross, total deductions and net pay compute automatically. Includes signature lines and an optional net-pay-in-words field. Download as PDF — no signup, no watermark.

Create strong random passwords of any length right in your browser. Four modes: random, pronounceable, numeric PIN, and pattern-based. See the entropy in bits and estimated time to crack. Exclude ambiguous characters. Bulk generate up to 500 at once.

Extract the dominant color palette from an image — upload a file or paste a public URL. Choose between 3 and 12 colors. See HEX, RGB, HSL and the percentage share of each color, then export the palette as ready-to-use CSS variables or JSON.

Estimate your baby's due date from your last menstrual period or the conception date. See your current week, trimester and the number of days remaining. Based on Naegele's rule — the standard 280-day count used by obstetricians.

Paste a Base64 string and see the decoded image instantly. Accepts raw Base64 or a full data URI — with or without the data:image/...;base64, prefix. Detects PNG, JPEG, GIF, WebP, BMP, SVG, ICO and AVIF from the data URI or the file's magic bytes. Download with the right extension.

Paste or upload a Base64 image and get back a smaller one. Control output format, maximum width and height, and quality — the tool re-encodes the image through the Canvas API. Handy for shrinking inline data URIs in HTML, CSS or JSON payloads.

Test JavaScript regular expressions with live highlighting. Matches appear as you type. Toggle all six flags — g, i, m, s, u, y — independently. See index, full match and capture groups for every match. Clear error messages for malformed patterns.

Convert between hourly, daily, weekly, monthly and annual pay in one place. Set your actual hours and days per week to get precise equivalents — no need to assume the standard 40-hour week.

Compress HTML, CSS or JavaScript by removing whitespace and comments. The language is detected automatically. JavaScript uses Terser in its safest mode — no variable renaming, no logic changes. See the size reduction in bytes after minifying.

Turn a single square image into a complete favicon set — 16, 32, 48, 96, 180, 192 and 512 px, covering browsers, iOS and Android. Get a ready-to-use site.webmanifest, an HTML link snippet, and a ZIP archive with all icons ready to drop into your public folder.

Format messy SQL into readable code or minify it into a single line for logs. Control keyword casing (UPPERCASE, lowercase or Preserve) and indentation level. Comments are kept in Format mode and stripped in Minify mode.

Compare two texts or code snippets by line, word, or character — differences are highlighted right in the text. Three comparison modes and two layouts for line-level diff: Split and Unified.

Work out gross margin, markup and target-margin pricing. Enter cost and price to get margin, markup and profit per 100 in sales. Or reverse it: enter a target margin or markup and get the selling price you need. Works with any currency.

Compress JPG, PNG, WebP and AVIF images without uploading anything. Drop up to 20 files, pick a quality level or a max width, and download the results individually or as a set. See original vs compressed size and savings percentage for each file.

Turn a plain screenshot into a polished visual. Add a solid or gradient background, rounded corners, an optional macOS-style window frame and a soft drop shadow. Six gradient presets included, plus custom colors and angles. Export as PNG, JPEG or WebP at up to 3× scale.