230+ Free Tools — No Sign-Up Required

UtilityToolsLabFree Friendly Online Utilities for Everyday Tasks

UtilityToolsLab is a free, friendly collection of online utility tools for everyday tasks. No sign-up, no nonsense. Just tools that work.

Text & Content

Case converters, counters, formatters and word tools

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Word Counter

Count words, characters, sentences, paragraphs, lines and reading time as you type, with live keyword density analysis. Free and private.

Case Converter

Convert text between UPPERCASE, lowercase, Title Case, Sentence case, camelCase, PascalCase, snake_case, and kebab-case.

Paragraph Formatter

Clean and reformat text by removing extra spaces, collapsing blank lines, trimming each line, or joining into a single line.

Keyword Density

Measure how often each word appears in your content, as a raw count and a percentage of total words, with the top 20 terms ranked as bars.

Text Reverser

Flip a block of text four ways: by character, by word order, by line order, or word order within each line, with original spacing preserved.

Lorem Ipsum

Placeholder text in 20 languages — English, Bengali, Hindi, Arabic, Spanish, French, Chinese and more. Paragraphs, sentences, words, lists, optional emoji.

English Lorem Ipsum

Generate free English Lorem Ipsum dummy text for web design, layouts, and mockups. Classic Latin filler text in paragraphs, sentences, words, or lists.

Bangla Lorem Ipsum

Generate free Bangla (Bengali) Lorem Ipsum dummy text for web layouts and mockups. Bengali script filler in paragraphs, sentences, words, or lists.

Image & Design

Compressors, color tools, CSS generators and more

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Image Compressor

Compress JPEG, PNG, and WebP images in your browser. Control quality and max dimensions — no server upload required.

HEX ↔ RGB

Convert color codes between HEX, RGB, RGBA and HSL instantly, with a live visual preview. Built for designers and CSS work — free, no sign-up.

QR Code

Generate QR codes from any URL, text, email or phone number instantly and download them as PNG. Free, no sign-up, and runs in your browser.

Color Palette

Generate harmonious color palettes from any base color. Supports complementary, triadic, analogous, and monochromatic schemes.

Gradient Generator

Generate linear, radial, and conic CSS gradients visually. Add unlimited color stops, adjust angles, use presets, copy ready CSS.

Contrast Checker

Check WCAG 2.1 contrast ratios between foreground and background. Shows AA/AAA pass/fail for normal and large text sizes.

Image Resizer

Resize any JPEG, PNG, WebP or GIF to exact pixels or a percentage. Locks the aspect ratio, steps down smoothly, re-encodes in your tab.

Format Converter

Re-encode PNG, JPEG, WebP, GIF, AVIF and BMP pictures into any of four formats, 20 files per run, with a matte colour behind transparency.

Code & Dev

JSON, Base64, UUID, JWT, timestamps and encoders

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JSON Formatter

Paste raw JSON to instantly format, beautify, validate and minify it. Syntax errors are pinpointed by line and column. Free and fully private.

Base64

Encode text or data to Base64 and decode Base64 strings back to readable text. A fast developer utility for API payloads, tokens and data URIs.

UUID Generator

Generate RFC 4122 compliant UUID v4 strings with one click, or batch-generate up to 100 unique IDs at once. Cryptographically random and free.

JWT Decoder

Decode and inspect JSON Web Tokens. View header, payload, and signature. Detects expiry and maps all registered JWT claims.

Timestamp

Convert Unix timestamps to human-readable dates and convert dates back to Unix time. Live clock with ISO 8601, UTC, and local formats.

Regex Tester

Test regular expressions live with highlighted matches, capture groups, and a plain-English breakdown of every token. Includes replace preview and flag toggles.

Random JSON Generator

Paste a JSON template and generate mock payloads with realistic random names, emails, UUIDs, dates and prices — your structure preserved exactly.

API Load Tester

Send batches of HTTP requests to any API endpoint and watch every response time land in a live log, with min, average, p95 and success-rate stats.

Math & Calc

Percentage, BMI, tip, temperature and unit converters

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Trig Calculator

All six trig functions in degrees, radians or gradians, with exact surd values, a unit circle, and honest undefined answers where tangent blows up.

Log Calculator

Compute a logarithm in any base, or solve for the base or argument, with change-of-base shown and the same log restated in base 10, e and 2.

% Calculator

Calculate percentages, percentage increase and decrease, and what percent one number is of another. Instant answers for discounts and grades.

BMI Calculator

Calculate your Body Mass Index (BMI) in metric or imperial units and see your health category instantly. Free, private, no sign-up required.

Tip Calculator

Calculate tip amounts and split bills between any number of people. Quick tip buttons, custom percentage, and per-person breakdown.

Temperature

Convert temperatures between Celsius, Fahrenheit, Kelvin, Rankine, and Delisle instantly. Common reference points included.

Age Calculator

Calculate your exact age in years, months, days, hours, and minutes from your date of birth. Shows total counts and next birthday countdown.

Loan Calculator

Calculate your monthly loan payment (EMI), total interest, and payoff date. Includes a full amortization schedule and an extra-payment savings breakdown.

Security

Password generators, hash tools and crypto utilities

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Password Generator

Generate cryptographically strong random passwords with custom length, symbols, numbers and uppercase options. Nothing is sent to any server.

Password Strength

Score a password against what crackers actually try — wordlists, keyboard walks, leet spelling, dates — and see how long four attacks would take.

Passphrase Generator

Generate memorable passphrases using crypto.getRandomValues. 3–10 words, 5 separator styles, capitalize & digit options. Live entropy meter.

Entropy Calculator

Calculate password entropy in bits from a real password or a length-and-character-set policy, then compare crack times across four attack speeds.

API Key Generator

Generate random API-style key strings for tests, mock UIs and seed data with a chosen prefix, encoding (hex, Base64URL, alphanumeric) and length.

PIN Generator

Generate cryptographically secure PINs in numeric, alphanumeric, or hex mode. Choose length 4–16, batch up to 20 PINs, and group digits for readability.

Secret Key Generator

Generate 128–512-bit cryptographic secret keys in hex, Base64, Base64URL, or Base58 using crypto.getRandomValues. Batch up to 20 keys at once.

Password Checker

Check a password against 10 structural weakness patterns — length, common words, keyboard walks, l33t-speak, year patterns and more. Runs locally.

Competitive Programming

Algorithms, Big-O analysis, I/O generators and code formatters for coders

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Code Formatter

Format and beautify C++, Java, and Python code with consistent indentation. 100% client-side — no code leaves your browser.

Matrix Generator

Generate grid/matrix inputs for competitive programming. Random, zeros, identity, or sequential fill. Outputs in multiple formats.

Complexity Calc

Estimate Big-O operations and runtime for any N. Interactive reference table for all complexity classes from O(1) to O(N!).

Bit Visualizer

Toggle 32/64-bit grids. Click bits to flip them live and see decimal recalculate. Shows popcountll, clzll, ctzll, and MSB instantly.

Bitmask Planner

Input set size N (≤12). Visualize all 2^N bitmasks, submask iterations, and generate ready-to-paste C++ DP skeleton.

Prime Factors

Input N to instantly view prime factorization, total divisors, Euler totient, and full sorted divisors list with prime highlighting.

MEX Calc

Input a comma-separated array and see the MEX (Minimum Excluded) computed step-by-step with frequency table and visual walkthrough.

Interval Merger

Input pairs of ranges like [1,4],[3,7]. Visualizes overlaps on a timeline and collapses them into merged segments instantly.

PDF Utilities

100% client-side PDF tools — no uploads, no servers, full privacy

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PDF Metadata

Instantly view PDF page count, version, author, title, and more. Parsed 100% in your browser — no upload required.

Images → PDF

Convert multiple JPG/PNG images into a single PDF. Reorder pages, then print-to-PDF using your browser. 100% client-side.

PDF to Text

Extract text from any PDF in the browser — powered by PDF.js. Works with modern PDFs from Chrome, Word and Acrobat. No upload, no server.

PDF Merger

Merge multiple PDF files into one in your browser. Drag to reorder pages, skip password-protected files automatically. No upload, no server.

PDF Splitter

Split a PDF in your browser: extract a page range, break it into fixed chunks, or save every page as its own file. No upload, no server, no sign-up.

PDF Rotator

Rotate all pages or a specific range in a PDF by 90°, 180° or 270°. Runs entirely in your browser — no upload, no account, no file size cap beyond 100 MB.

PDF Watermark

Stamp text across a PDF with your own size, angle, colour and opacity. Nine anchor positions or a tiled fill, on every page or a range you pick.

PDF Compressor

Compress a PDF in your browser by stripping metadata and packing object streams. Saves 10–40% on Office/LaTeX PDFs. No upload, no account needed.

Productivity

Greeting generators, planners, timers and daily workflow helpers

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Time Greeting

Generate Good Morning, Afternoon, Evening or Night messages from any timezone — your device, UTC, or US Eastern, Central, Mountain and Pacific.

Pomodoro Timer

Stay focused with a Pomodoro timer: 25-minute work sessions, short and long breaks, session dots, and a sound alert — all configurable, all in your browser.

Task Prioritizer

Sort tasks into the Eisenhower Matrix: Do First, Schedule, Delegate, or Eliminate. Tasks persist in localStorage across browser restarts.

Focus Timer

Set a 1-to-240-minute countdown for deep work sessions. Adjustable in 5-minute steps, six quick presets, sound alert, and a daily sessions-completed stat.

Habit Tracker

Track daily habits on a GitHub-style 84-day grid with current and longest streaks, completion rate, and color coding. Saved locally, no account.

To-Do List

Add tasks, set High / Medium / Low priority, filter by status, and track progress with a live completion bar. Saves to your browser automatically.

Online Notepad

A distraction-free notepad that saves to your browser as you type. Keep up to 20 notes, watch the word count live, download any note as Markdown.

Standup Notes

Fill in Yesterday, Today and Blockers, then copy as plain text or Markdown. Saves to your browser and keeps a 7-entry history of past standups.

Writing & Editing

Speech synthesis, readability tests and drafting aids

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Speech to Text

Dictate into a live transcript using your microphone and browser's Web Speech API. Supports 20 languages, punctuation chips, editing, copy and download.

Text to Speech

Convert typed or pasted text into spoken audio using your browser's built-in voices, with adjustable rate, pitch, volume, and live word highlighting.

Keyword Extractor

Extract the top single words or 2- and 3-word phrases from any text, ranked by frequency and share, with adjustable stopword and length filters.

Text Similarity

Compare two documents with cosine, Jaccard and character edit-distance scores, plus the words unique to each side and every phrase they share.

Style Checker

Highlights passive voice, hedges, -ly adverbs, nominalisations, filler phrases and sentences past 25 words in your own draft, colour-coded and counted.

Encryption & Keys

AES file encryption, key pairs and certificate tooling

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AES File Encryptor

Encrypt or decrypt any file with a passphrase using AES-256-GCM and PBKDF2 key derivation, entirely in your browser. Nothing is uploaded.

RSA Key Generator

Generate RSA key pairs (2048, 3072, 4096-bit) for encryption (OAEP) or signing (PSS) in PEM format using WebCrypto. Download or copy instantly.

ECDSA Key Generator

Generate ECDSA or ECDH key pairs on P-256, P-384, or P-521 in PEM or JWK format using WebCrypto. Private key blurred by default. Nothing uploaded.

Cert Decoder

Paste a PEM certificate and read its subject, issuer, validity dates, SANs, key algorithm and SHA-256 fingerprint. Decoded in your browser only.

CSR Generator

Generate a PKCS#10 CSR and matching private key in your browser. Supports RSA 2048/4096 and EC P-256/P-384. Nothing is uploaded or transmitted.

Auth, Privacy & Validation

2FA codes, cookie inspection, sanitisers and validators

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Suspicious URL Check

Read a link before you click it: decodes punycode, spots the @ trick, mixed-script homographs and brand-in-subdomain. The link is read, never fetched.

2FA QR Builder

Build the otpauth:// URI for a TOTP or HOTP account and render it as a scannable QR code. SHA-1/256/512, 6–8 digits, 30–90s period. Nothing uploaded.

TOTP Generator

Generate time-based one-time passcodes from a Base32 secret using RFC 6238, entirely in your browser. Configure the algorithm, digit count, and refresh period.

Card Validator

Validate any card number with the Luhn algorithm. Detects Visa, Mastercard, Amex, Discover and more. Shows IIN, CVC length, and formatted display.

Email Validator

Check one address or a whole list for syntax errors, mistyped providers, disposable domains and role accounts. Nothing is uploaded or looked up.

Crypto Wallets & Keys

Mnemonics, HD derivation, address validation — all offline

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Keystore Inspector

See which account a wallet keystore holds and how strong its scrypt or PBKDF2 work factor is. No password field, and nothing is ever decrypted.

BIP-39 Generator

Generate a BIP-39 mnemonic seed phrase from secure entropy, entirely in your browser. Choose 12 to 24 words and verify the checksum against the spec.

Wei/ETH Converter

Convert between all 10 Ethereum denominations — Wei, Gwei, Szabo, Finney, ETH and more — with BigInt precision and instant copy for every result.

ETH Validator

Validate any Ethereum address, check its EIP-55 mixed-case checksum, and copy the checksummed, lowercase, or uppercase form. Runs offline.

BTC Validator

Check any Bitcoin address for a valid checksum and see its type, network and witness program. Legacy, SegWit and Taproot, all offline.

Smart Contracts & EVM

ABI, selectors, Merkle proofs, gas and EIP-712 tooling

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Function Selector

Compute the 4-byte Ethereum function selector from a Solidity signature using Keccak-256, entirely in your browser. Paste names or types.

Gas Fee Calculator

Calculate Ethereum gas fees in ETH and USD. Supports EIP-1559 (base fee + tip) and legacy gas price. Six transaction type presets included.

ENS Namehash

Compute the ENS namehash (EIP-137) for any .eth domain, label by label, using Keccak-256 in your browser. See every recursive hashing step.

Merkle Tree Builder

Build a Keccak-256 Merkle tree from an address allowlist, read off the root, and copy an inclusion proof for any leaf. OpenZeppelin sorted pairs.

ABI Encoder

Encode a Solidity function call to calldata or decode raw calldata to typed values. Supports uint/int, bool, address, bytesN, bytes and string. No upload.

Blockchain Encoding

Keccak, RLP, Base58, Bech32 and CID utilities

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RLP Encoder

Decode a raw Ethereum RLP payload into its fields, or serialise a nested structure back into bytes. Shows every item, length prefix and nesting level.

Base58 Encoder

Encode bytes or text to Base58 and Base58Check, or decode a Base58 string back to hex with a full checksum check. Runs entirely in your browser.

Keccak-256

Compute the Keccak-256 hash of text or raw hex bytes entirely in your browser — the Ethereum variant, not NIST SHA-3. No uploads, ever.

EIP-55 Checksum

Apply or validate the EIP-55 mixed-case checksum on any Ethereum address. Shows checksummed, lowercase, and uppercase forms with instant copy.

Satoshi/BTC

Convert between Satoshi, Bit, mBTC and BTC with BigInt precision. No floating-point rounding at the satoshi level, no price feed, no network call.

DeFi & Tokenomics

Impermanent loss, staking, APY, vesting and mining maths

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Token Supply

Convert ERC-20 token amounts to the base-unit integer a contract call takes and back, and measure any holding against total supply. BigInt-exact.

Vesting Planner

Turn an allocation, cliff and vesting period into a dated unlock schedule with a cumulative curve and CSV export. Handles both cliff conventions.

Impermanent Loss

Model the impermanent loss from a 50/50 liquidity pool as one token's price moves, entirely in your browser, with dollar amounts, not just percent.

APY/APR Converter

Convert APY to APR or APR to APY across 8 compounding frequencies. Shows the formula, result, and a full comparison table. Includes continuous compounding.

Staking Rewards

Project staked crypto growth over any period at a given APR, with simple or compounding payout. See total rewards, effective APY and a balance timeline.

On-Page SEO

Meta tags, canonicals, hreflang, SERP preview and slugs

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Hreflang Generator

Build hreflang tags for every language version of a page as HTML, an HTTP header or sitemap XML, and catch invalid codes like en-UK before they ship.

SERP Preview

Preview how a title and description will look in Google search results, with real pixel-width truncation, not just a character count. 100% client-side.

Meta Tag Generator

Generate title, description, canonical, robots, Open Graph, and Twitter Card meta tags in one place. Copy the HTML and paste into your page head.

robots.txt Generator

Build a valid robots.txt file from Allow/Disallow rule groups, crawl-delay and sitemap URLs. Multiple user-agents supported. Copy and paste, entirely offline.

Keyword Permutations

Combine word lists into every long-tail keyword phrase, one term from each. Join character, list-order permutation and Google Ads match-type wrapping.

Schema & Structured Data

JSON-LD generators for FAQ, product, event, recipe and more

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LocalBusiness JSON-LD

Build LocalBusiness JSON-LD with opening hours modelled properly: split shifts, merged day ranges and round-the-clock trading all come out correct.

Article Schema

Build Article, BlogPosting or NewsArticle JSON-LD with author, publisher and date properties. Flags a headline over Google's 110-character limit.

FAQ Schema

Build a schema.org FAQPage JSON-LD block from your own questions and answers, ready to paste into your page. 100% client-side, no uploads.

Breadcrumb Schema

Build a schema.org BreadcrumbList JSON-LD block from an ordered page trail, ready to paste into your page. 100% client-side, no uploads.

Product Schema

Build a schema.org Product JSON-LD block with brand, SKU, price, availability and star ratings. Empty fields are dropped, so the markup stays valid.

Marketing & Ad Calculators

UTM, CTR, CPC, CPM, CPA, CLV, CAC and A/B significance

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CLV Calculator

Work out customer lifetime value three ways, with the LTV to CAC ratio and payback month, and see why zero churn breaks the usual formula.

A/B Significance

Run a two-proportion z-test on your A/B test results and get a real p-value, not just a percentage. Fully client-side, no data ever leaves your device.

CTR Calculator

Calculate click-through rate from clicks and impressions, set a target CTR to see the click gap, and compare against common channel benchmarks. Offline.

CPM Calculator

Solve for CPM, impressions or ad spend from the other two, with a target-CPM gap, cost per impression and common channel benchmarks. No ad-platform login.

UTM Builder

Tag any link with utm_source, utm_medium and campaign parameters, or paste a finished link and read its fields back out. Existing query strings survive.

Number & Base Tools

Primes, factorials, base conversion, matrices and randomisers

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Matrix Calculator

Add, subtract, multiply, transpose, and find the determinant or inverse of a 2x2 or 3x3 matrix. No data ever leaves your device.

Random Numbers

Draw whole numbers from any range using your device's cryptographic random source, with unique-values mode and the modulo bias rejected rather than ignored.

Dice Roller

Roll d4 through d100 with standard dice notation like 2d6+3, a running history, and cryptographically random results. No physical dice required.

Fibonacci Generator

Generate the Fibonacci sequence up to F(200) with exact BigInt precision. Shows golden-ratio convergence, a visual bar chart, and copy as CSV or lines.

Prime Checker

Check whether any positive integer is prime, with the full prime factorisation when it is not. Trial division to ⌈√n⌉ — deterministic and exact.

Date & Time Tools

Differences, time zones, timers, clocks and working days

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Date Difference

Get the exact calendar difference between two dates in years, months and days, plus total days, weeks, hours and minutes.

Time Zone Converter

Convert any date and time across 40 IANA time zones simultaneously. DST handled automatically. Copy any result with one click. No server, no sign-up.

Date Add / Subtract

Add or subtract years, months, weeks, days, hours and minutes from any date. Month-end clamping, ISO week number and a copyable ISO 8601 stamp.

Countdown Timer

Live countdown to any date and time in days, hours, minutes and seconds. Shows total hours and minutes too. Past dates switch to elapsed time automatically.

Time Card Calculator

Calculate worked hours and overtime from clock-in, clock-out and break data. Supports night shifts, daily and weekly OT caps, and optional gross pay.

Gaming Tools

Stylish name generators, font pickers, and symbol palettes for mobile games

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FF Name Generator

Type any nickname and get 70+ stylish Free Fire variants across 8 Unicode fonts and 9 border frames. One-click copy on every result. No sign-up.

Free eBooks

Downloadable PDF guides and study books, free and without signup

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500 Verbs (Bangla)

Free 108-page PDF: 500 everyday English verbs with Bangla pronunciation, meaning and an example sentence each. No email, no signup.

Why these tools exist

Most of these tools started as a scratch file. Preparing for programming contests, we kept rewriting the same throwaway snippets: a submask enumerator here, a matrix generator there. Working on backend code, we kept pasting API responses into whichever JSON formatter came up first in the search results. That second habit is the one that started to bother us. A JWT is a credential. A request body is often somebody else's customer data, and neither belongs in a text box on a server nobody here knows anything about.

So we rebuilt the ones we needed and kept them local. UtilityToolsLab is where they ended up: 234 tools, each one running inside the page you already have open. Your input is handled by JavaScript in your own tab and nothing is posted anywhere, which is a claim you can check rather than trust. Open the network panel, paste a payload into the JSON formatter, and watch for a request that never fires.

That single constraint decides what is here and what is missing. A whois lookup or a link shortener genuinely needs a server, so neither one exists here and neither one will. What is here instead is the long tail we reach for on an ordinary working day: Base64 and URL encoding, timestamp conversion, WCAG contrast ratios, EMI schedules, convex hulls, segment tree scaffolding. If a tool behaves oddly, or you need one that is not on this list, the Facebook page linked in the footer is the fastest way to reach us.

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