Free online tools

0-9

• 2-column / 3-column notes (T-chart) PDF generator
  Create 2- or 3-column note paper in millimeters. Adjust column ratios, headers, and ruled or dot guides, then print or save as PDF.

A

• Accessible Color Palette Generator
  Build a role-based accessible palette from one approved base color, then review surface, text, accent, and button contrast before final UI decisions.
• Add Page Numbers & Watermarks to PDF
  Add page numbers or text watermarks to a PDF in your browser.
• Algebra Worksheet Generator
  Create printable algebra handouts with answer keys and optional worked steps.
• Annotation paper PDF generator (comment margin)
  Create annotation paper with an adjustable comment margin and ruled, dot, or blank guides in millimeters, then print to PDF or share exact layout settings by URL.
• Aspect Ratio Calculator
  Simplify image or video ratios, solve a missing width or height, and preview contain, cover, and crop behavior inside one box.

B

• Base64 Encode / Decode Tool
  Encode text to Base64, decode Base64 to text, and convert files to Base64 or data URI locally in your browser.
• Best Meeting Time Across Time Zones
  Find overlapping meeting windows across time zones with ranked suggestions and a shareable plan.
• Beta Distribution Generator & Visualizer
  Generate random samples from a Beta distribution and visualize the PDF and histogram.
• Bingo card generator (printable)
  Generate printable bingo cards and call lists in your browser.

C

• Calligraphy guide sheet PDF generator
  Adjust x-height/ascender/descender ratios, slant angle (52–55°), unit lines, vertical guides, and left margin lines for calligraphy practice.
• Card deck shuffler – shuffle & draw cards
  Shuffle a deck of playing cards and draw or deal cards in your browser.
• Chinese character grid (Tianzige / Mizhige) PDF
  Generate Tianzige/Mizhige practice grids in millimeters. Adjust rows, columns, cell size, bold lines every 5 cells, line colors, and header/footer for A4/B5/Letter.
• Clock Tools: Meeting Planner, Unix Timestamp, Timer
  Browse clock and time tools for meeting planning, Unix timestamp conversion, military time conversion, timers, alarms, and fullscreen displays.
• Color Converter
  Convert one color between HEX, RGB, HSL, and a matching common color keyword.
• Color Difference Checker
  Compare two colors by RGB distance and a simple perceptual ΔE76 gap, then review HEX, RGB, and HSL values in your browser.
• Color Harmony Generator
  Generate analogous, complementary, triadic, or split-complementary color sets from one base color, then copy HEX, RGB, or HSL values in your browser.
• Color Mixer
  Blend two colors by ratio, then inspect the mixed result in HEX, RGB, HSL, and a matching common color keyword when available.
• Color Palette Generator
  Generate quick tints, shades, tones, and accent colors from one base color, then inspect HEX, RGB, and HSL values in your browser.
• Color Picker
  Pick a color and read HEX, RGB, HSL, plus quick contrast checks against black and white.
• Color Scale Generator
  Build a quick 5, 7, or 9-step color scale from one base color, preview each step, and copy HEX, RGB, or HSL values in your browser.
• Color Temperature Checker
  Check whether one color reads warm, cool, or neutral, then compare a slightly warmer and cooler variation in your browser.
• Color Token Audit
  Audit one token-ready color set before export. Check contrast failures, duplicate roles, and overly similar token pairs in light and dark mode.
• Color Token Diff
  Compare two token-ready color sets role by role. See changed token slots, contrast drift, and where the next palette differs from the current one before export.
• Color Token Export Generator
  Start from one approved brand color, then export light and dark role palettes as CSS variables, JSON tokens, and a Tailwind-like map for handoff.
• Color Token Naming
  Stabilize semantic, component, state, and theme token naming before audit or export.
• Color Token Preview
  Preview light and dark tokenized UI cards before exporting CSS variables or JSON tokens.
• Column Arithmetic Worksheet Generator
  Build printable column-arithmetic worksheets for addition, subtraction, multiplication, division, decimal multiplication, and decimal division with seeded variants and answer keys.
• Compare Two PDFs – Find Text Differences in Browser
  Select two PDFs, extract their text in your browser, and highlight added or removed lines or paragraphs.
• Component Color Tokens
  Turn approved role colors into component aliases such as button, card, input, nav, and badge tokens.
• Contrast Checker
  Check contrast ratio for foreground and background colors, then see quick WCAG AA/AAA verdicts for normal and large text.
• Cornell notes PDF generator – cue/notes/summary layout
  Generate Cornell notes paper as SVG in millimeters. Adjust cue/notes/summary/header sizes, choose ruled/dot/blank guides, then print or save to PDF.
• CSS Color Mix Generator
  Build a ready-to-paste CSS color-mix() string from two known colors, then preview the mixed result in OKLCH or sRGB.
• CSV Column Profiler
  Paste CSV or TSV data to inspect column types, missing values, unique counts, and next chart or stats options.

D

• Dice stats (odds & distribution) + PNG sharing
  Compute odds and distributions for NdS +/- K. Auto switches Exact/Sim, shows a histogram, and lets you share as text, PNG, or URL — in your browser.
• Dice tools – roller, TRPG checks, dice stats
  Browser-only dice tools: dice roller, TRPG checks, and dice stats for odds and distributions.
• Dirichlet Distribution Generator & Visualizer
  Generate probability vectors from a Dirichlet distribution and visualize marginals and simplex plots.
• Distribution Sampler and Histogram Tool
  Generate random samples from common distributions, visualize histograms, review summary stats, and export CSV/JSON.
• Dot grid paper PDF generator – printable SVG in mm
  Generate dot grid paper as an SVG in millimeters. Adjust dot spacing, dot size, opacity, margins, calibration box, and guide markers.

E

• Embed Builder — share links & iframe code
  Create CalcBE share links and responsive iframe embeds. Supports presets, UTM tags, base64url cfg, optional hash mode, and an auto-height snippet.
• Engineering paper PDF generator
  Generate engineering paper with 4/5/10 squares per inch converted to millimeters.
• Epoch Converter
  Quickly parse Unix epoch seconds, milliseconds, or ISO 8601 dates into UTC and browser local time.
• Event Countdown (Time Remaining)
  Show time remaining until a target date/time with an analog + digital display.

F

• Flashcard / index card PDF generator (cut guides)
  Auto-arrange 3x5, 4x6, A7, and custom index cards on one page with cut lines or crop marks, then print a precise layout as SVG or PDF for flashcards and study sets.
• Float Inspector Tool
  Inspect IEEE 754 bit layouts for float16, bfloat16, float32, and float64.
• Free online tools for PDF, images, text, and random tasks
  Open browser-based tools for PDF work, image cleanup, worksheets, text formatting, and random picks.
• Free PDF Tools – Compress, Merge & Convert in Browser
  Compress, merge, split, and convert PDFs free in your browser.
• Free QR code generator & scanner – create, verify
  Generate QR codes for URLs, text, Wi-Fi, contacts, phone, email, and SMS.
• Fullscreen Clock
  Show a large fullscreen clock in your browser with analog and digital views, seconds toggle, timezone options, and dark mode.
• Fullwidth/Halfwidth Katakana Converter (Zenkaku/Hankaku)
  Convert Japanese text between fullwidth/halfwidth and Hiragana/Katakana in your browser.

G

• Genko yoshi manuscript paper PDF generator
  Generate genko yoshi manuscript paper with configurable page size, margins, character grid settings, and print-friendly SVG output for handwriting practice or class.
• Gradient Generator
  Build quick linear or radial CSS gradients from 2 or 3 colors, preview the result, and copy the CSS string in your browser.
• Graph paper PDF generator
  Generate print-ready SVG graph paper in millimeters: Cartesian, polar, log-log, semilog, and isometric grids with How it's generated steps and CSV export.

H

• Habit Tracker Paper (Printable PDF)｜CalcBE
  Generate monthly or yearly habit tracker paper as precise millimeter SVG with weekday labels, weekly separators, and goal rows.
• Hash Generator Tool
  Generate SHA-1, SHA-256, and SHA-512 hashes for text or files in your browser.
• Hex Grid Paper Generator (Printable PDF, flat-top/pointy-top)
  Generate printable hex grid paper as PDF or SVG. Choose flat-top or pointy-top orientation, millimeter spacing, line weight, and margins — all in your browser, no upload.

I

• Image Resizer & Format Converter
  Resize and convert images in your browser. Set width, height, format, and quality, then download—no uploads.
• Interval Timer (HIIT & Tabata)
  Analog + digital interval timer for HIIT/Tabata. Work/rest, rounds/sets, warm-up/cooldown, count-in, sound, and notifications supported.
• IPv4 subnet & CIDR calculator – network address, host
  Convert any IPv4 address and prefix length into its network address, broadcast address, usable host range, and total capacity.

J

• JPG/PNG to PDF – Convert Images in Browser
  Convert JPG, PNG, and WebP images into one PDF in your browser.
• JSON Diff Tool
  Compare two JSON documents online by structure. See added keys, removed keys, changed values, and parse errors locally in your browser.
• JSON Formatter & Validator
  Pretty-print, minify, and validate JSON in your browser. Highlight errors and copy formatted results without sending data to a server.

L

• Likert Scale Calculator
  Paste per-option survey counts and get n, mean, median, mode, standard deviation, Top-2-Box, Bottom-2-Box, NPS split, and distribution bars.
• Lined paper PDF generator – ruled paper in mm
  Generate lined (ruled) paper as an SVG in millimeters. Adjust line spacing, margins, margin lines, bold lines, calibration box, and hole-punch guide.
• List Shuffler (Random Order Generator) – fair shuffle
  Shuffle a list fairly with Fisher–Yates. Copy results, share a URL, and optionally reproduce the same order with a seed—runs locally in your browser.

M

• Merge PDFs – reorder and combine multiple files locally
  Merge PDF files in your browser, reorder them, keep only selected page ranges, and download one combined PDF without uploading files.
• Military Time Converter: 24 Hour to 12 Hour, AM/PM
  Convert military time to AM/PM and AM/PM to 24-hour time instantly.
• Multi Timer
  Manage multiple countdown timers at once with analog + digital views, fullscreen focus, sound/notifications, presets, saving, and sharing.
• Multiplication Table Generator
  Generate printable multiplication tables for 1-12, 1-20, custom sizes, blank practice sheets, skip counting, and answer keys with a reproducible seed.

N

• Number Bonds Builder
  Build number bonds to 10, 20, 100, or any target, then print missing-part worksheets, answer keys, and fact families with part-whole diagrams.
• Number line & interval visualizer (inequality shading)
  Shade inequalities and interval unions on an interactive SVG number line.

O

• OKLCH Converter – HEX, RGB, HSL to OKLCH & OKLab
  Convert one color between HEX, RGB, HSL, OKLCH, and OKLab, then copy perceptual color values for modern design-token workflows in your browser.
• Online Alarm Clock
  Set alarms in your browser without installing apps. Supports repeats, snooze, sound, notifications, and fullscreen.
• Online Dice Roller (d4-d100, 2d6+3)
  Roll d4 to d100 or use notation like 2d6+3. See totals and roll breakdowns, keep local history, and share as text or PNG. No sign-in.
• Online Stopwatch with Analog + Digital Display
  Run a high-precision stopwatch with analog and digital displays, lap tracking, fullscreen, keyboard shortcuts, and a shareable settings URL.
• Online Timer (Countdown)
  Set an online countdown timer with analog and digital displays, presets, quick adjustments, fullscreen, keyboard shortcuts, and a shareable settings URL.

P

• Paper templates hub (lined, grid, Cornell, to-do)
  Find lined paper, dot grid, Cornell notes, to-do sheets, habit trackers, graph paper, and more.
• Passphrase generator (Diceware-style) – random words
  Generate a strong passphrase from random words (Diceware-style) locally in your browser.
• Password generator – strong secure random passwords
  Generate strong random passwords in your browser with crypto.getRandomValues.
• Pattern String Generator — business IDs & sequences
  Generate business-style IDs from a pattern (date, sequence, random).
• PDF compressor – shrink large PDF files in your browser
  Reduce PDF size entirely in your browser. Choose quality presets or custom DPI/quality, convert to grayscale, and download instantly without uploading files.
• PDF Form Filler & Flattener – Fill, Flatten & Download
  Fill PDF form fields in your browser, preview detected AcroForm controls, choose editable or flattened output, and download without uploads.
• PDF highlighter & annotator – markup in browser
  Annotate a PDF in your browser with highlights, pen marks, and text notes.
• PDF Metadata Editor – View, Edit & Clear Metadata
  View, edit, or clear PDF title, author, subject, keywords, and date metadata in your browser without changing the page content.
• PDF page organizer – reorder, rotate & delete pages
  Reorder, rotate, duplicate, or delete PDF pages in your browser.
• PDF to EMF converter – preserve vectors & text
  Convert PDF to EMF in your browser for Windows Office and drawing workflows.
• PDF to Images – Convert Pages to PNG or JPG
  Convert PDF pages to PNG or JPEG in your browser. Choose DPI, export all pages or a range, and download each image or a ZIP without uploads.
• PDF to SVG – Editable Vector Graphics in Browser
  Convert PDF pages to SVG in your browser for editable, scalable vector graphics.
• PDF to text converter – extract text in browser
  Extract selectable text from PDFs in your browser. Keep per-page output or merge pages, choose layout or paragraph mode, and download TXT without uploads.
• Permutation test – exact p-value for A/B and paired
  Run a permutation (randomization) test for two independent groups or paired samples.
• Pomodoro Timer with Analog & Digital Display
  Run a pomodoro timer with analog and digital displays, automatic phase transitions, local stats, fullscreen, keyboard shortcuts, and a shareable settings URL.
• Primary handwriting paper PDF generator (3-line)
  Generate primary handwriting paper with headline + dashed midline + baseline.
• Print DPI Calculator
  Estimate effective PPI for a print size from image pixels. Compare horizontal, vertical, and target PPI before resizing or ordering a print.

Q

• Query String Parser
  Parse raw query strings or full URLs, inspect repeated keys, decode values, and copy a normalized query locally in your browser.
• Quick charts from pasted data — scatter / box plot
  Paste spreadsheet data to generate scatter and box plots instantly.

R

• Random CSV generator – test data & schema JSON
  Generate random CSV test data in your browser. Define columns, preview rows, then download CSV and schema JSON — no uploads and share settings-only URLs.
• Random Date Generator, Time Generator & Datetime Generator
  Generate random dates, random times, or random datetimes with ranges, weekday filters, exclusions, time windows, and step sizes for QA, test data, or schedule sampling.
• Random distributions: samplers, tests & visualizers
  Generate random samples from distributions, visualize histograms, and sanity-check randomness in your browser.
• Random JSON Generator (Test Data) — array & NDJSON
  Generate JSON test data from a schema. Export as JSON array or NDJSON. Runs locally in your browser — no uploads; share settings-only URLs.
• Random Log Generator — Nginx, Apache & JSON logs
  Generate fake access logs (Nginx/Apache) or JSONL logs with controllable distributions.
• Random number generator (integers, decimals, seed)
  Generate random numbers in your browser: integers or decimals, optional seed, unique mode, and one-click copy.
• Random Picker
  Pick one or more random items from a list in your browser. Great for lotteries, giveaways, and classroom activities. Everything runs locally without sending data to a server.
• Random SQL INSERT Generator — Postgres, MySQL, SQLite
  Generate SQL INSERT statements from a schema for Postgres, MySQL, or SQLite.
• Random test data generators (CSV, IDs, time)
  Create CSV test data, random IDs, and timestamps locally in your browser.
• Random tools – generators, pickers, shuffles
  Random generators and pickers that run entirely in your browser: numbers, dates, CSV test data, tokens, UUIDs, shuffles, and verifiable draws.
• Random Walk & Markov Chain Visualizer
  Run random walk (1D/2D/3D) and Markov chain simulations in your browser.
• Randomness beacon verifier – paste a beacon to verify
  Paste a public beacon value to verify a deterministic draw or shuffle.
• Randomness Tests (chi-square, runs, ACF, JB)
  Run chi-square, runs, autocorrelation, and Jarque-Bera tests on bit or number sequences.
• Regex Tester Tool
  Test JavaScript regular expressions online with pattern, flags, match preview, capture groups, and replace output.
• Resize & Crop PDF Pages – A4, Letter, Custom
  Crop and resize PDF pages in your browser. Draw a crop area, pick a target size (A4, Letter, or custom), add margins, and export—no uploads.

S

• Seating Chart Generator (Random) — Classroom & Tables
  Free online seating chart generator for classrooms and events.
• Secret Santa generator (exclusions) – draw names fairly
  Generate Secret Santa assignments in your browser. Add blocked pairs and groups, then reveal recipients one by one to reduce accidental leaks.
• Semantic Color Tokens
  Turn an approved base color into semantic token names for product UI, docs, or marketing.
• Seyes (French ruled) paper PDF generator
  Generate Seyes/French ruled paper in millimeters. Standard 2 mm minors + 8 mm majors, 8 mm verticals, red margin line, enlarged 3 mm/12 mm, A4/B5/Letter.
• Shuffle bias comparison – naive vs Fisher–Yates
  Compare shuffle bias: naive swap-everywhere vs Fisher–Yates (and optional sort(() => random - 0.5)).
• Sign a PDF – Add Signature & Approval Stamp
  Create a drawn or image signature, place it on PDF pages, add dates or approval stamps, and export a flattened PDF in your browser.
• Split PDF files – extract page ranges or every N pages
  Split a PDF into multiple files directly in your browser. Use page ranges, one-per-page, or every N pages, then download each file or all as a ZIP.
• Staff paper PDF generator
  Generate staff paper in millimeters. Adjust staff spacing, system count (auto/manual), bar guides, lyric lines, and title fields.
• State Color Tokens
  Turn approved component token aliases into hover, active, disabled, focus, or selected state tokens.
• Step-by-step solution PDF exporter — multi-language
  Build printable, step-by-step solution sheets with numbering styles, language options, and attachments.
• Study timetable (time blocking) PDF generator
  Create daily or weekly time-blocking timetables in millimeters with adjustable columns, labels, and margins, then print clean SVG or PDF sheets for planning routines.
• Synthetic Time Series Generator — trend, seasonality
  Generate synthetic time series data with trend, seasonality, noise, missing values, and outliers.

T

• TAB sheet PDF generator
  Generate guitar/bass TAB sheets in millimeters. Set string count, spacing, auto/manual systems, bar/beat guides, tuning boxes, and A4/B5/Letter paper.
• Team generator – random teams & groups
  Split a list of names into random teams or groups in your browser.
• Text Case Converter — upper/lower/title
  Convert text between upper, lower, title, sentence, snake_case, camelCase, and kebab-case instantly in your browser.
• Text Diff Tool
  Compare two plain text blocks online line by line. Review added lines, removed lines, unchanged lines, and optional trailing-whitespace handling locally in your browser.
• Theme Color Tokens
  Turn one approved base color into light, dark, brand-alt, and high-contrast token bundles.
• Todo checklist paper PDF generator (printable)
  Generate printable todo/checklist paper with checkboxes. Adjust columns, row height, due/priority/notes fields, and a 50 mm calibration square in millimeters.
• Token Alias Planner
  Plan token alias depth and fallback chains across semantic, component, state, and theme layers before naming, audit, or export.
• Token Category Mapper
  Decide whether a token belongs in semantic, component, state, or theme layers before naming, audit, or export.
• Token Conflict Checker
  Check where one token role creates direct conflicts, shadowed overrides, and redundant layers across theme, state, and platform scenarios.
• Token Counter
  Count characters, words, lines, bytes, and rough token estimates for mixed English and CJK text.
• Token Dependency Graph
  Map upstream aliases and downstream token dependents so you can see what breaks before renaming, replacing, or exporting one source token.
• Token Deprecation Plan
  Turn token change scope into a deprecation plan with alias grace, warning channel, freeze timing, and hard-removal steps before rollout.
• Token Fallback Map
  Map fallback order, override winner, and last-resort source when semantic, component, state, and theme tokens can all answer the same role.
• Token generator – secure random strings (base64url, hex)
  Generate secure random tokens and random strings locally in your browser.
• Token Impact Simulator
  Simulate which branches, tokens, and component surfaces change first when you rename, replace, or remove one token source.
• Token Migration Status
  Track token adoption, replacement coverage, blockers, and remaining consumers before freeze, deprecation, and removal.
• Token Override Matrix
  Compare how one token role changes winners across theme, state, and platform scenarios after fallback order already looks believable.
• Token Resolution Debugger
  Trace one token from public request through alias hops, layer candidates, and last-resort fallback so you can explain exactly why the final value won.
• Token Rollout Checklist
  Turn token impact estimates into a release checklist for visual diff, coverage, docs, and blocker review before merge or production rollout.
• Triangular Distribution Generator (min/mode/max)
  Generate samples from a triangular distribution using min/mode/max and visualize the PDF and histogram.
• TRPG dice check (d20/d100, pools) with PNG sharing
  Run d20/d100 checks with advantage/disadvantage, compare vs DC, and roll dice pools to count successes.
• Truncated Normal Generator & Visualizer
  Generate samples from a truncated normal distribution with lower/upper bounds and visualize the PDF/CDF and histogram.

U

• Unix Timestamp Converter & Epoch to Date Converter
  Convert Unix epoch seconds or milliseconds to human-readable date/time and back.
• URL Encoder / Decoder Tool
  Percent-encode text, decode strings, and parse full URLs with an editable query parameter list in your browser.
• UUID Generator (v4/v7) – bulk, format, validate
  Generate UUID v4 or UUID v7 in bulk, format them (canonical/URN/braces), copy or download, and validate UUIDs with v7 timestamp decoding—runs locally in your browser.

V

• Verifiable random draw (commit-reveal) – auditable
  Run a verifiable random draw with commit-reveal logs so participants can verify every draw.

W

• Weibull Distribution Generator & Visualizer
  Generate random samples from a Weibull distribution and visualize the PDF and histogram.
• Weighted Random Picker & Randomizer
  Use this weighted random picker and randomizer to draw winners by weight, ratio, or raffle entries.
• World Clock Board (Multiple Time Zones)
  Compare multiple city times with analog + digital clocks, work-hour highlights, shareable URLs, and JSON export/import.