159+ Developer Tools
Mawu (Oltool, oltool.net) is a free online developer toolbox with 182 privacy-first utilities: encryption, Base64, JSON/YAML conversion, regex tester, QR code generator, IPv4 subnet calculator, JWT parser, and more. All processing happens locally in your browser - no data is ever uploaded to a server.
Mawu (Oltool, oltool.net) is a developer-focused online toolbox launched in 2025, now featuring 182 practical tools across nine categories: cryptography, converters, text processing, math, networking, web tools, PDF tools, image tools, and data conversion. We are committed to privacy-first principles - every tool runs entirely in your browser, with no registration, no installation, and no data leaving your device. Whether you need to quickly parse a JWT token, generate an RFC 4122-compliant UUID, or diff two JSON config files, you will find the right tool here. Forever free, continuously updated.
Popular Tools
View all →Topic Hubs 5
JSON Tools Collection
Format, minify, validate, convert, generate types and query JSON from one focused entry page.
Encoding Online — Free Encoding & Decoding Tools
Base64, URL encoding, HTML entities, Unicode, binary, JWT and Basic Auth utilities in one place.
Network Tools Collection
IP, CIDR, MAC, ports, User-Agent, URL and HTTP status utilities for everyday diagnostics.
Crypto & Hash Tools Collection
UUID, ULID, tokens, hashes, HMAC, Bcrypt, AES, RSA, OTP and password strength tools in one entry.
Developer Tools Collection
API debugging, data conversion, regex testing, Git reference, Markdown, SQL, Docker, Cron and SEO meta tools.
Popular Reference Sheets
View all →Crypto 12
UUID Generator
Free online UUID v4 & GUID generator — cryptographically secure, runs locally in your browser. Create random unique IDs for database keys, API tokens, and sessions in one click. No signup, no upload.
Hash Generator
Generate SHA-1, SHA-256, SHA-384, SHA-512 hashes from text with hex output, plus MD5 and RIPEMD-160. Perfect for checksums and file integrity verification.
HMAC Generator
Compute HMAC signatures with SHA-1/256/384/512 algorithms for API authentication and request signing. Perfect for webhook signatures and API auth flows.
Token Generator
Generate random secure tokens with custom charset, length, and hex or base64 output. Flexible enough for API keys, sessions, nonces and one-time links.
Bcrypt Hash
Hash and verify passwords with bcrypt using custom salt rounds from 4 to 12. Industry-standard password hashing with an adjustable work factor.
Password Strength Analyser
Estimate password strength, entropy bits and crack time using zxcvbn analysis. Spot weak passwords before they reach production systems and accounts.
BIP39 Passphrase
Free online BIP39 mnemonic generator — create 12/15/18/21/24-word seed phrases for crypto wallets, compatible with Bitcoin, Ethereum and all HD wallet standards. Runs locally, no upload.
Encrypt / Decrypt Text
AES-GCM encrypt and decrypt text with a passphrase via the browser-native Web Crypto API. Keys are derived from the passphrase with PBKDF2 (SHA-256); all processing stays local in your browser.
RSA Key Pair Generator
Generate RSA key pairs in PEM format via the Web Crypto API with 1024-4096 bit keys. Web Crypto native, exportable PEM keys for any stack or service.
ULID Generator
Generate sortable Universally Unique Lexicographic IDs (128-bit, timestamp-based). Time-ordered IDs that sort naturally in databases, logs and indexes.
OTP / TOTP Generator
Generate TOTP codes (RFC 6238) from a base32 secret for 2FA and MFA authentication. Drop-in 2FA codes matching Google Authenticator and Authy output.
PDF Signature Checker
Inspect digital signature metadata embedded in a PDF with X.509 certificates. Verify signer identity and certificate chain without uploading your file.
Converter 40
Base64 Encoder / Decoder
Encode text to Base64 or decode Base64 back to plain text with full UTF-8 support. Instant bidirectional conversion with one-click copy for any string.
URL Encoder / Decoder
Encode or decode URL-safe strings using percent-encoding for query params and path segments. Essential for building safe query strings and REST URLs.
Case Converter
Convert text between camelCase, snake_case, kebab-case, PascalCase and CONSTANT_CASE instantly. Switch naming styles for code, configs and identifiers.
Integer Base Converter
Convert numbers between binary, octal, decimal, hex and any base from 2 to 36. Real-time results for low-level programming, bitwise ops and math homework.
Roman Numeral Converter
Convert between Arabic numbers (1-3999) and Roman numerals instantly. Handy for chapters, outlines, clock faces, movie sequels and classic notation.
Color Converter
Convert colors between HEX, RGB and HSL formats with full alpha channel support. Alpha-aware color translation for CSS, design tools and style guides.
Unix Timestamp Converter
Convert between Unix timestamps and human-readable dates with ISO 8601 output. Essential for log analysis, API debugging and cross-timezone work.
Text to Binary
Convert text to binary or back via UTF-8 encoding for ASCII and Unicode characters. Handy for low-level debugging, encoding tutorials and CTF puzzles.
Text to Unicode
Convert text to Unicode escape sequences (\uXXXX) and back for UTF-16. Ideal for debugging encoded strings and inspecting raw code points easily.
Text to NATO Alphabet
Convert text to NATO phonetic alphabet (Alpha, Bravo, Charlie) for clear radio and phone communication. Spell out words letter by letter with confidence.
YAML to JSON
Convert YAML data to formatted JSON with full nested structure support. Drop in config files for clean indented JSON you can paste anywhere.
JSON to YAML
Convert JSON data to YAML format with custom indentation and nested object support. Turn verbose JSON configs into clean readable YAML in seconds.
JSON Formatter
Beautify, minify and validate JSON data with syntax error detection. Catch malformed brackets and commas before they break your API integration.
XML Formatter
Pretty-print and validate XML documents with custom indentation for readable configs, SOAP payloads and API response debugging and troubleshooting sessions.
SQL Formatter
Format and indent SQL queries with a regex-based prettifier for SELECT, INSERT and UPDATE statements to keep database code clean and readable.
HTML Formatter
Format and beautify HTML code with proper indentation. Supports DOCTYPE, void elements, raw text elements. Beautify or minify. 100% client-side.
CSS Formatter
Format and beautify CSS code with proper indentation. Supports @media, @keyframes and nested rules. Beautify or minify. 100% client-side.
JS Formatter
Format and beautify JavaScript code with proper indentation. Handles functions, loops, arrow functions, template literals. Beautify or minify. 100% client-side.
JSON to CSV
Convert a JSON array of objects to CSV with custom delimiters and headers for spreadsheet import, data export and pipeline interoperability.
JSON Diff
Compare two JSON documents and highlight deep differences with an inline view for spotting API response changes and configuration drift issues.
docker run to compose
Convert a docker run command into docker-compose.yml with ports, volumes and env vars for migrating ad-hoc containers to managed orchestration stacks.
List Converter
Sort, dedupe, reverse and transform lists with custom separators and case conversion for cleaning up pasted data and performing bulk text edits.
JSON Minify
Compact JSON by stripping whitespace and newlines for smaller file size, faster network transfers and reduced payload overhead in API responses.
JSON to XML
Convert a JSON document to XML with a custom root element and attributes for legacy system integration, SOAP APIs and enterprise data exchange.
XML to JSON
Convert an XML document to JSON via DOMParser with attribute and namespace support for modernizing legacy API responses and config file processing.
JSON to TOML
Convert JSON to TOML config format with nested tables, arrays and typed values for Rust, Python and other project configuration file generation.
TOML to JSON
Parse a TOML document into JSON with tables, arrays, dates and multiline strings for inspecting, debugging and migrating configuration files.
YAML to TOML
Convert YAML data to TOML format with nested structures and typed values for switching config formats across different toolchains and projects.
TOML to YAML
Convert TOML data to YAML format with nested tables, arrays and dates for Kubernetes configs, CI pipeline definitions and deployment manifests.
Base64 File Encoder
Encode any local file to a Base64 data URL for images, PDFs and binary files to embed assets directly in HTML, CSS and JSON data payload strings.
JSON to TypeScript
Generate TypeScript interfaces from sample JSON with nested types, arrays and optional fields for typing API responses and configuration objects.
JSON to JSON Schema
Generate a JSON Schema (Draft-07) from sample JSON with properties, required fields and array items for runtime validation and API contract docs.
JSON to Go Struct
Convert sample JSON to Go structs with json tags, nested types and omitempty option for typing API clients, config loaders and data model definitions.
JSON to Java
Generate Java classes from sample JSON with nested types, List generics, getters/setters and JsonProperty annotations for REST API clients and DTOs.
JSON to Python
Generate Python dataclass or TypedDict from sample JSON with nested types, List generics and Optional fields for API response typing and config parsing.
JSON to C#
Generate C# classes from sample JSON with nested types, List generics, nullable reference types and JsonProperty attributes for .NET API clients and models.
Lunar Calendar Converter
Convert Gregorian and Chinese Lunar calendar dates with zodiac, Gan-Zhi (天干地支), solar terms and leap month support for festival planning and almanac lookup.
Punycode Converter
Convert international domain names to Punycode (xn--...) and back with full RFC 3492 support. Encode IDN domains for DNS and DNS-unsafe ASCII lookup, decode xn-- domains to Unicode.
Unicode Escape Converter
Convert text to Unicode escape sequences (\uXXXX and \u{XXXXX} ES6) and back. Handles surrogate pairs for emoji, supports bidirectional text-to-escape and escape-to-text conversion.
Barcode Generator
Generate barcodes in 20+ formats: CODE128, EAN13, EAN8, UPC, CODE39, ITF14, MSI, pharmacode and more. Download as PNG or SVG. 100% client-side.
Web 28
HTML Entities
Encode or decode HTML entities (&, <, >, ", ') for safe rendering. Prevent XSS and keep templating output clean and correct.
Slugify String
Make strings into URL-safe slugs (lowercase, hyphens, ASCII) with unicode normalization. Build clean permalinks for blogs and docs in one click.
JWT Parser
Decode and inspect JWT tokens (header, payload, expiry) with signature check. Inspect auth claims and expiry without sending secrets anywhere.
MIME Type Lookup
Look up MIME types by file extension or vice versa for common formats (json, pdf, png). Set correct Content-Type headers and avoid broken downloads.
HTTP Status Codes
Reference for HTTP status codes (1xx-5xx) with meanings, examples and use cases. Debug API responses faster by looking up 404, 503 and every code.
URL Parser
Parse a URL into protocol, host, path, query, hash components with query parsing. Break links apart for redirects, analytics and quick debugging.
Basic Auth Generator
Free online Basic Auth generator — turn a username and password into a Base64 Authorization header for curl, Postman and nginx in one click. Decode existing credentials too. Runs locally, no upload.
QR Code Generator
Generate QR codes as PNG data URL from text or URLs with custom colors and sizes. Embed links, contacts and Wi-Fi creds in scannable images.
Crontab Generator
Free online crontab generator — build cron expressions with a visual editor and see the next run times and plain-language meaning instantly. Debug Linux crontab and Kubernetes CronJobs. No login, no setup.
Open Graph Meta Generator
Generate meta tags for SEO, Open Graph and Twitter cards with live preview. Make your share links look right on Facebook, X and search results.
Safelink Decoder
Free online safelink decoder — decode Outlook / Office365 safelink URLs back to their original URLs in batch. Strip tracking wrappers and recover real links from email safely. Runs locally, no upload, no signup.
IBAN Validator
Validate IBAN with mod-97 checksum and parse country and bank info for SEPA countries. Verify international account numbers before making payouts.
JSON Tree Viewer
Browse a large JSON document as a collapsible tree with search and path copy. Drill into deep API responses and copy any node path instantly.
YAML Viewer
Render YAML with collapsible structure and syntax highlighting. Navigate large config files and jump between keys without losing your place.
SVG Placeholder Generator
Generate SVG placeholder images as data URLs with custom size, colors and text. Mock up layouts and prototypes without any real assets ready.
Wi-Fi QR Code Generator
Generate QR codes that auto-connect to a Wi-Fi network with full WPA/WEP support. Let guests join your network by scanning instead of typing.
Emoji Picker
Browse and copy popular emojis by category with search and skin tone support. Find the right reaction and paste it into chat, commits or docs.
Keycode Info
Show the key code and event details for any keypress (keyCode, key, code, location). Build shortcuts and game controls with the right codes.
Device Information
Display browser, OS, screen, GPU and runtime info with viewport, pixel ratio and more. Debug responsive layouts and feature detection on the fly.
Camera Recorder
Record video and audio from your webcam using MediaRecorder with WebM/MP4 output. Capture quick clips and demos without installing anything.
Open Graph Meta Generator
Build Open Graph and Twitter Card meta tags with live preview and social sharing. Preview exactly how cards render before you ship the page.
cURL to Code
Convert cURL commands to Python, JavaScript, PHP, Go, Java code with auth and JSON body. Turn terminal snippets into runnable client code fast.
JSONPath Finder
Test and extract data from JSON with JSONPath expressions in real time, with examples and match count for building and debugging complex queries.
JavaScript Runner
Run JavaScript code directly in your browser with console output capture. Safe sandboxed execution, no setup needed. Perfect for quick experiments and learning.
User-Agent Parser
Parse and analyze User-Agent strings. Auto-detect your current browser UA or parse any custom UA. Shows browser, OS, device, engine and CPU info.
Image Cropper
Crop images to precise dimensions or aspect ratios (1:1, 16:9, 4:3) with a drag-to-select editor. Export as PNG, JPEG or WebP - all processing in your browser, no upload.
Image Watermark
Add text watermarks to images with position, opacity, font size and rotation control. Tile watermarks across the whole image or place in a corner. PNG, JPEG, WebP export.
Color Palette Generator
Generate color palettes from a base color with complementary, analogous, triadic and monochromatic schemes. Output HEX, RGB and HSL values, export as JSON, CSS or TXT.
Text 25
Text Statistics
Count characters, words, lines, bytes and estimate reading time with sentence analysis to gauge content length and overall readability at a glance.
String Obfuscator
Obfuscate text by replacing middle characters with asterisks for emails, phones and credit cards to protect sensitive data in logs and screenshots.
Markdown Preview
Render Markdown to HTML in real time with markdown-it, GFM, code blocks and tables, a live writing companion for documentation and README files.
ASCII Banner (Figlet)
Generate large ASCII-art text banners with figlet fonts and custom styles, perfect for terminal headers, code comments and retro decorations.
Numeronym Generator
Convert words to numeronyms like i18n, k8s, a11y and l10n for compact abbreviations used across tech documentation and engineering shorthand.
String Pluralizer
Convert English nouns between singular and plural forms, including irregular nouns, for dynamic labels and grammatically correct UI text and output.
Email Normalizer
Normalize emails by lowercasing, removing Gmail dots and plus-aliases with RFC validation for deduping mailing lists and cleaning user records.
Text Diff
Compare two text blocks line-by-line using the LCS algorithm with inline highlighting to review edits and merge conflicting changes side by side.
Regex Tester
Test JavaScript regular expressions with flags like g, i, m, s and u plus capture groups for building, debugging and validating match patterns.
Regex Cheatsheet
Quick reference for JS regex syntax, character classes, anchors and quantifiers, a handy cheat sheet for writing and debugging match patterns.
Git Cheatsheet
Quick reference for common git commands like init, commit, branch, merge and rebase for daily version control workflow and troubleshooting lookups.
HTML WYSIWYG Editor
Visual rich-text editor that outputs clean HTML with bold, italic, lists and links for drafting emails, blog posts and content management systems.
Fake Data Generator
Generate realistic mock data: names, emails, phone numbers, addresses, companies and IDs in JSON or CSV format for testing, prototyping and database seeding.
AI Prompt Generator
Generate structured AI prompts with role, task, context, tone and format constraints. Create high-quality prompts for ChatGPT, Claude, and other LLMs without guessing.
Text to Speech
Convert text to speech using the Web Speech Synthesis API. Choose from available voices, adjust speed and pitch. 100% browser-based, no upload needed.
Lorem Ipsum Generator
Generate Lorem Ipsum placeholder text or Chinese filler copy as paragraphs, sentences or words. Configurable count, classic opening line, download as TXT.
Text Replacer
Find and replace text with support for case-sensitive matching, whole word matching and regular expressions. Replace all occurrences at once with live preview.
URL Extractor
Extract all URLs from any text. Automatically detects http, https, www and bare domain links. Deduplicate and export results as a list.
Email Extractor
Extract all email addresses from any text. Validates format and removes duplicates. Export as comma-separated or line-separated list.
Duplicate Line Remover
Remove duplicate lines from text while preserving order. Case-sensitive or case-insensitive mode. Shows count of duplicates removed.
Empty Line Remover
Remove empty or blank lines from text. Optionally trim whitespace from each line. Compact text output instantly.
Chart Generator
Create bar charts from your data. Paste CSV or JSON data, customize colors, labels and download as PNG. ECharts-powered, 100% client-side.
Line Chart Generator
Create line charts from CSV or JSON data. Multiple series, smooth curves, area fill. Download as PNG. ECharts-powered.
Pie Chart Generator
Create pie charts and donut charts from your data. Custom colors, labels, legend. Download as PNG. ECharts-powered, client-side.
Image OCR
Extract text from images using Tesseract.js. Supports 60+ languages including Chinese, English, Japanese. 100% client-side, no upload. Paste or upload image.
Math 12
Percentage Calculator
Calculate percentages, increase or decrease, ratios and change between values with multiple modes for everyday math and financial quick checks.
Math Evaluator
Evaluate math expressions safely without eval, supporting functions, operators and parentheses for quick calculations and formula prototyping.
Date Calculator
Add or subtract days, diff dates and format dates with date-fns and time zone support for scheduling, planning and project deadline tracking.
Temperature Converter
Convert between Celsius, Fahrenheit, Kelvin and Rankine with decimal precision for science homework, cooking recipes and weather comparisons.
ETA Calculator
Compute estimated time of arrival from rate and remaining work with custom units for sprint planning and long-running task progress projections.
Chmod Calculator
Convert between octal and rwx Unix permission notation with special bits support for setting secure file and directory permissions on servers.
Chronometer / Stopwatch
Stopwatch with start, pause, lap and reset at millisecond precision for timing tasks, workouts, presentations and benchmarking code execution.
Benchmark Builder
Compare multiple operations-per-second measurements and rank them with statistical analysis to identify the fastest performing code approach.
Unit Converter
Convert length, weight, area, volume, speed and data storage units across metric and imperial systems with instant bidirectional swap for any task.
Stats Calculator
Compute count, sum, mean, median, mode, min, max, range, variance and standard deviation from a list of numbers for data analysis and stats homework.
Compound Interest Calculator
Calculate compound interest with regular monthly contributions, adjustable compounding frequency and final amount, total principal and return rate.
Timezone Converter
Convert any moment between world time zones with a live world clock for UTC, Shanghai, Tokyo, London, New York, Los Angeles and Sydney.
Network 12
MAC Address Generator
Free online MAC address generator — bulk-create spec-compliant random MACs with vendor OUI prefix, colon/hyphen/dot separators, and correct unicast & LAA bits. Runs locally in your browser, no install, no signup, no registration.
Random Port Generator
Free online random port generator — pick valid non-system ports (1024–65535) in one click, with bulk export, dedupe and range filtering. No signup, runs in your browser.
IPv4 Subnet Calculator
CIDR calculator showing network, broadcast, host range, mask and wildcard for any prefix from /0 to /32, essential for network planning and firewalls.
Phone Parser & Formatter
Parse, validate and format international phone numbers into E.164 with country codes for contact forms, CRM imports and data cleanup workflows.
User-Agent Parser
Parse User-Agent strings into browser, OS and device info with Chrome, Firefox and Safari detection for analytics and compatibility debugging.
IPv6 ULA Generator
Generate IPv6 unique local addresses in the fd00::/8 range with custom subnet and EUI-64 for homelabs, internal networks and private infrastructure setups.
IPv4 Address Converter
Convert IPv4 between dotted, decimal, hex and binary formats with reverse DNS for network debugging, protocol analysis and subnet calculations.
IPv4 Range Expander
Expand CIDR notation to a full list of individual IP addresses with bulk export for firewall rules, network scans and access control setups.
MAC Address Vendor Lookup
Free online MAC OUI vendor lookup — identify the manufacturer behind any MAC address using the IEEE database. Spot unknown devices on your local network in seconds. Runs locally, no upload, no signup, no registration.
IP Query
Look up IP address information including country, region, city, ISP and coordinates. Auto-detect your current IP or query any IP address. Free API.
DNS Lookup
Query DNS records (A, AAAA, MX, TXT, NS, CNAME, SOA, CAA) via Google or Cloudflare DoH and inspect name, type, TTL and data in one click.
Bandwidth Calculator
Compute download time, speed or file size from the other two with Mbps, Gbps, MB, GB and TB units, perfect for estimating transfer durations.
Data 5
Data Format Converter
Convert between JSON, YAML, TOML, XML and CSV in one place with a single paste and instant preview for multi-format config and data conversion.
Excel to JSON
Convert Excel files (xlsx, xls, csv) to JSON format. Supports nested headers, sheet selection and key mapping. 100% client-side with SheetJS.
Excel to CSV
Convert Excel files to CSV format with custom delimiter options. Batch convert multiple sheets. Pure browser processing with SheetJS.
Excel to HTML
Convert Excel files to clean HTML tables with styling. Sheet selection and responsive table output. 100% client-side.
Excel to Text
Extract plain text from Excel files. Tab-separated or custom delimiter output. Batch process multiple sheets. Client-side only.
Image 11
Image Compressor
Compress PNG, JPEG and WebP images in your browser with an adjustable quality slider, batch processing and before-and-after file size preview.
Image Format Converter
Convert images between PNG, JPEG and WebP formats with quality control and white background fill for JPEG transparency and compatibility handling.
Image Color Picker
Pick colors from any image with an eyedropper tool, get HEX, RGB and HSL values and maintain a running history of all your sampled color values.
Image Resizer
Resize images to custom width and height while optionally maintaining aspect ratio. Support PNG, JPEG, WebP input and output with quality control. 100% client-side canvas processing, no upload.
Image Merger
Combine multiple images into one. Horizontal or vertical layout, custom gap and background color. PNG, JPEG, WebP support. Canvas-based.
Image Round Corners
Add rounded corners to images with customizable radius. PNG output with transparency. Canvas-based, 100% client-side.
Image Border
Add borders to images with custom width, color and style. Solid, dashed or dotted borders. PNG, JPEG, WebP output. Canvas-based.
Image to ICO
Convert PNG, JPEG or WebP images to ICO favicon format. Multi-size ICO support (16x16 to 256x256). Download as .ico file. Client-side.
Image to GIF
Convert multiple images to an animated GIF. Set frame delay, loop count and order. PNG, JPEG, WebP input. gif.js-powered, client-side.
GIF Compressor
Compress animated GIFs by reducing colors, frame rate and dimensions. Preview before and after size. 100% client-side.
GIF Cropper
Crop animated GIFs to a specific area. Visual selection with adjustable rectangle. Preserves animation. Canvas-based, client-side.
PDF 14
PDF Merger
Merge multiple PDF files into one document in your browser. Drag-and-drop reorder, page count preview, instant download. 100% client-side with pdf-lib, no upload.
PDF Splitter
Split a PDF by page ranges or extract individual pages. Preview page count, export selected pages as a new PDF. Pure browser processing with pdf-lib.
PDF Rotator
Rotate PDF pages 90, 180, or 270 degrees. Select specific pages or rotate all. Download the rotated PDF instantly. Client-side only, no server upload.
PDF Watermark
Add text watermarks to PDF documents with custom font, size, color, opacity, rotation and position. Tile across all pages or place in corner. 100% browser-based.
PDF Encrypt
Add password protection to PDF files. Set user password and owner password with permissions control. 100% client-side, no upload.
PDF Decrypt
Remove password protection from PDF files. Enter the current password to unlock and download. Client-side processing only.
PDF Page Numbers
Add page numbers to PDF documents. Customize position, font size, format and starting page. 100% browser-based with pdf-lib.
PDF Page Deleter
Delete specific pages from a PDF. Select pages to remove and download the cleaned PDF. Pure client-side processing.
PDF to Image
Convert each PDF page to a PNG or JPEG image. Download all pages as a zip or individual files. 100% client-side rendering.
PDF Compress
Compress PDF files with three quality levels. Remove metadata and thumbnails to reduce file size. Before/after comparison. 100% client-side.
PDF Page Organizer
Reorganize PDF pages: drag to reorder, delete unwanted pages. Visual page grid with thumbnails. Download the cleaned PDF. Client-side only.
PDF Extract
Extract specific pages from a PDF by page range. Choose pages to keep and download as a new PDF. Custom range input. Pure browser processing.
PDF Sign
Add electronic signatures to PDF documents. Draw signature with mouse/touch or upload a signature image. Customize position and size. 100% client-side.
PDF Crop
Crop PDF pages to remove white margins or adjust visible area. Auto-detect margins or set custom values. Apply to all or selected pages. Client-side.