Why OctalOne
Privacy-first, Offline-capable utilities
Zero Uploads
Files never leave your device — full privacy by design.
Offline Ready
Load tools once and keep working without an internet connection.
Simple UI
Drag-and-drop, progress indicators, and safe downloads only when ready.
Image to PDF
Convert and merge JPG, PNG, HEIC, and WebP images to a single PDF. Choose page size, margins, layout. 100% private.
Image Compressor
Compress JPG, PNG, WebP images instantly. Reduce file size by up to 90%. No uploads, 100% private.
Image Resizer
Resize images by pixel dimensions or percentage. Optional aspect ratio lock. 100% private.
Image Converter
Convert images between JPG, PNG, WEBP, BMP, ICO, GIF, AVIF, and SVG instantly. 100% private, client-side conversion.
Image Rotator
Rotate and flip images instantly in your browser. Batch rotate 90°, 180°, 270° or flip. 100% private.
Image Info Viewer
Extract and view hidden EXIF metadata (camera settings, GPS, software) from your images securely in your browser.
Image Color Picker
Pick colors from images with pixel precision, extract dominant palettes, inspect HEX/RGB/HSL, check WCAG contrast, and export swatches.
Image Cropper
Crop images online with custom aspect ratios, social media presets, circular crop, zoom & rotation. 100% private, client-side.
PDF Merge
Combine multiple PDFs into one. Drag to reorder, preview pages, download instantly. 100% private.
PDF Split
Break a PDF into multiple chunks and download them as a ZIP.
PDF Info & Metadata Viewer
Extract and view hidden PDF metadata, properties, and page sizes securely in your browser.
Unlock PDF
Remove password and unlock protected PDF files instantly in your browser. 100% private & client-side.
Lock PDF
Lock and password protect PDF files securely in your browser. Add 128-bit encryption, restrict printing, and batch lock multiple PDFs. 100% private & offline.
Compress PDF
Reduce PDF file size while maintaining quality. Choose presets or target specific file sizes with 100% client-side privacy.
Remove Pages from PDF
Delete and remove unwanted pages from PDF files online. Select specific pages or enter page ranges with 100% client-side privacy & offline capability.
EMI Calculator
Plan EMIs, interest, and the amortization schedule for home, car, personal, and education loans.
SIP Calculator
Calculate returns on SIP or Lumpsum investments with inflation adjustment.
CAGR Calculator
Calculate the Compound Annual Growth Rate (CAGR) of an investment or business metric instantly.
Percentage Calculator
Calculate percentages, percentage change, increase, decrease, and proportions with interactive 100-square grid, donut gauge, and step-by-step methods.
Discount Calculator
Calculate final prices after applying single or multiple stacked discounts and sales tax.
Prime Number Checker
Check if any integer up to 10^32 is prime or composite. Instant primality test, prime factorization, and nearest primes.
Square Calculator
Calculate the square of any number (x²) instantly. Interactive visual grid, slider, facts, and precision math for students & adults.
Square Foot Calculator
Calculate square footage (sq ft) for rooms, flooring, landscaping, and 6 geometric shapes with dynamic SVG blueprints, material pricing, waste factor, and multi-room tracking.
Cubic Feet Calculator
Calculate volume in cubic feet (cu ft), cubic yards, gallons, and cubic meters for 12+ 3D shapes with interactive 2D blueprints and 3D spatial orbit visualizers.
Permutation Calculator
Calculate permutations (nPr) instantly with step-by-step arithmetic, interactive 'Order Matters' visualizer, and BigInt precision.
Combination Calculator
Calculate combinations (nCr) and combinations with repetition instantly with interactive Pascal's triangle, BigInt precision, and step-by-step methods.
BMI Calculator
Calculate Body Mass Index (BMI), Oxford New BMI, BMI Prime, and Ideal Body Weight with interactive SVG gauges, silhouette visualizer, and WHO classification standards.
Age Calculator
Calculate exact chronological age, next birthday countdown, planetary ages on Mars & Jupiter, life stages, and age differences.
LCM Calculator
Calculate the Least Common Multiple (LCM) and GCD for 2 to 10 numbers with interactive leapfrog number line race, prime factor Venn diagram, division ladder, and step-by-step methods.
GCD / GCF Calculator
Calculate the Greatest Common Divisor (GCD), GCF, and HCF for 2 to 10 numbers with interactive Euclidean rectangle tiling blueprint, prime factor Venn diagram, and 4 step-by-step methods.
Common Factors Calculator
Find all common factors (common divisors) for 2 to 10 numbers with interactive Venn diagram, factor rainbows, GCF, and 4 step-by-step methods.
Random Number Generator
Generate truly random or reproducibly seeded random numbers with cryptographic CSPRNG, seeded Mulberry32, unique sampling, frequency histogram, and chi-square stats.
Voltage Calculator
Calculate voltage (V = IR), Ohm's law, wire voltage drop, and resistor dividers with interactive circuit schematic, electron flow visualizer, and step-by-step methods.
Time Calculator
Calculate duration between two times, add/subtract time, calculate work hours and overtime payroll, convert time units, and calculate pace & speed.
Velocity Calculator
Calculate speed (v = d/t), constant acceleration SUVAT kinematics, circular & angular velocity, orbital escape speed, and relativistic mechanics with interactive vector visualizers.
Weight on Other Planets Calculator
Calculate your weight on the Moon, Mars, Jupiter, and all solar system planets. Explore gravity, jump heights, fall times, and custom exoplanet physics offline.
Triangle Calculator
Free online triangle calculator. Solve SSS, SAS, ASA, AAS, and SSA ambiguous triangles. Calculate sides, angles, area, altitudes, medians, incircle, and circumcircle with interactive SVG visualizers.
JSON Beautifier
Paste or drop JSON and get a validated, prettified result on the right side (client-side).
JSON Viewer
View, explore, and interact with JSON data in a collapsible tree format. Client-side and secure.
HTML Formatter
Beautify HTML snippets with a simple client-side formatter.
XML Formatter
Format and indent XML documents with CDATA, comments, and syntax error validation.
CSS Formatter
Format CSS code with a lightweight client-side formatter.
JavaScript Formatter
Format JavaScript code in the browser (lazy-loads Prettier if available).
TypeScript Formatter
Format and beautify TypeScript and TSX code with proper indentation and type alignment.
SQL Formatter
Format, indent, and beautify SQL queries across PostgreSQL, MySQL, SQLite, T-SQL, and BigQuery.
YAML Formatter
Format, indent, and validate YAML configurations for Kubernetes, Docker, and CI/CD pipelines.
GraphQL Formatter
Format and beautify GraphQL queries, mutations, fragments, and schema definitions.
Markdown Formatter
Format Markdown documents, align GFM tables, and clean up lists and code fences.
Diff Checker
Compare code, text, and JSON files side-by-side or inline using Monaco's advanced AST-aware diff algorithm.
Base64 Converter
Encode and decode Base64 data instantly. Supports UTF-8 characters.
Base64 URL Converter
Encode/Decode URL-safe Base64 strings (JWT safe).
URL Encoder
Percent-encode or decode URLs/strings instantly.
JSON Escape/Unescape
Escape text for JSON strings or unescape JSON strings.
Markdown Viewer
Preview Markdown files and encoded HTML instantly.
String Escape/Unescape
Escape/Unescape string literals (Java, JS, etc).
JWT Decode
Decode and inspect JSON Web Tokens (JWT).
Fake Credit Card Generator
Generate synthetic Luhn-valid test card data locally in your browser.
Password Generator
Generate cryptographically secure passwords, memorable XKCD passphrases, and PINs with entropy stats.
JSON Minifier
Minify, compress, and compact JSON data online for free. Remove unnecessary whitespace, comments, and newlines with 100% client-side privacy.
JSON to YAML Converter
Convert JSON data to formatted YAML and vice versa in real time. Features dual syntax highlighting, bidirectional swap, and 100% client-side privacy.
Stay chill
No files leave your device
Every tool includes drag-and-drop, loading states, and downloads that only appear when results are ready. Files never leave your device; processing happens in the browser.
Offline-first
Tip: load any tool, then turn off your internet — the tools continue to run completely offline.