Certificate Decoder

Decode X.509 SSL/TLS certificates in your browser: subject, issuer, SANs, validity, key usage, fingerprints, OCSP/CRL URLs. Verify chains and hostnames.

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More free developer tools

JSON & Data

Format, convert, diff and validate data

CSV Viewer – Free online tool to view your csv file.
JSON CSV Converter – Format JSON data to CSV and CSV to JSON format with our free online converter.
JSON Diff – Compare JSON data with our free online JSON diff tool.
JSON Prettify/Compress – Use our free JSON Formatter tool to beautify, validate, compress and edit JSON data online. Perfect for developers!
JSON Query (jq / JSONPath) – Free online jq playground and JSONPath tester. Filter, transform and extract data from JSON with jq 1.8 (WebAssembly) or JSONPath, entirely in your browser with snippets, history and shareable links.
Json Schema Validator – Validates provided json data against provided json schema
JSON to Language Converter – Convert JSON to PHP arrays, Python dictionaries, or Javascript objects, etc. effortlessly with our free online tool. Ideal for developers!
JSON Visualizer – Visualize JSON into interactive graphs
JSON-XML Converter – Convert your json data to XML and vice versa
JSON-YAML Converter – Easily convert YAML to JSON and JSON to YAML with our free online tool including support for yaml anchors. Fast and accurate conversion for developers.
Json/JsonSchema -Typescript Converter – Convert your Json data or Json Schema to Typescript
SQL Formatter – Format, beautify and minify SQL online with dialect-aware rules for MySQL, PostgreSQL, SQLite, SQL Server, Oracle, BigQuery, Snowflake and more. Keyword casing, indentation and line-width options, parse-error hints and shareable links. Runs entirely in your browser.
XML Prettify/Compress – Use our free XML Formatter tool to beautify, validate, compress and edit XML data online. Perfect for developers!
Yaml Lint-Formatter – Validate and format YAML files with our free online tool. Ideal for developers and content creators.

Encoding & Security

Encoders, hashes, tokens and certificates

Base64 Encoder/Decoder – Encode and decode Base64 with our free online tool. Supports text conversions for developers.
CSR Decoder – Decode certificate signing requests easily from your browser with our free online tool.
CSR Generator – Generate certificate signing requests easily from your browser with our free online tool.
Encryption & Key Generator – Generate RSA, ECDSA and Ed25519 keys as PEM, JWK or OpenSSH with fingerprints, encrypt text with AES-GCM or RSA-OAEP, sign with HMAC or keys and mint secrets.
JWT Sign/Verify – Decode, Sign and verify JWT tokens with our free online tool.
Number Base & Bitwise Calculator – Convert between binary, octal, decimal, hex and any base with arbitrary precision, run bitwise AND/OR/XOR/NOT and shift operations with a bit-by-bit view, inspect bit flags, calculate chmod permissions and subnet masks, break down IEEE 754 single/double floats, and render numbers as Roman numerals, words, bytes or Devanagari digits.
Password Generator – Generate strong and secure passwords with our free online password generator. Ideal for creating unique and random passwords for various applications.
Secret Hash – Generate secure hashes, HMAC, Scrypt, Blowfish, Bcrypt, PBKDF2 with our free online tool.
SRI Hash Generator – Generate sha256/384/512 Subresource Integrity hashes for CDN scripts and stylesheets from a URL, file or pasted code, with the HTML tag and a verifier.
URL Encoder/Decoder – Encode and decode URLs with our free online tool
URL Parser & Query Editor – Parse any URL into protocol, host, port, path, query and fragment, edit query parameters live, build URLs and UTM campaign links, and export as JSON, cURL or JavaScript. Free online tool.
UUID Generator – Generate unique identifiers with our free online UUID generator. Ideal for creating unique and random identifiers for various applications.

Code & Text

Beautify, preview and generate text

Code Beautify – Beautify and format JavaScript, HTML, CSS and SQL code with our free online tool.
Developer Test Data – List of test data for developers, qa engineers and product people to use in their development and testing processes.
Docker Run ↔ Compose – Convert docker run commands to docker-compose.yml and back, mapping ports, volumes, env, networks, healthchecks and GPUs, with warnings for unsupported flags.
HTML Viewer – View HTML code and render it online
HTML-Markdown Converter – Convert HTML code to Markdown and Markdown to HTML format with our free online converter.
LLM Token Counter – Count tokens as understood by LLM models with our free online tool.
Lorem Ipsum – Generate lorem ipsum text content with our free online tool.
Markdown Editor & Preview – Write GitHub-flavoured Markdown with a live side-by-side preview, syntax-highlighted code, tables and task lists. Open .md files, autosave drafts, and export to Markdown, HTML, rich text or PDF.
Meta Tags & Social Preview – Generate HTML meta tags, Open Graph, Twitter cards, canonical and JSON-LD, preview links on Google, Facebook, X, Slack, Discord and WhatsApp, and audit any page HTML.
Optical Character Recognition – Recognize text from uploaded file
Regex Tester – Test JavaScript regular expressions online with live match highlighting, capture group tables, find and replace, a plain-English pattern explainer and code snippets for JavaScript, Python, Go, Java, PHP and Rust.
Text & String Utilities – Convert text case (camelCase, snake_case, kebab-case, Title Case), slugify URLs, sort and dedupe lines, count words and characters, escape strings for JSON, HTML, SQL and shell, and clean Unicode with our free online text tools.
Text Diff Checker – Compare two texts or files online and highlight added, removed and changed lines with word-level differences. Side-by-side or unified view, ignore case and whitespace, export as patch or HTML.
Unicode Inspector – Inspect code points, UTF-8 bytes, escapes and blocks. Strip zero-width spaces, bidi controls and homoglyphs, normalize NFC and split Nepali aksharas.

Date & Time

Timestamps, cron and clocks

Cron Parser – Parse classic and extended cron expressions with our free online tool.
Date and Time – Find the current time and date of all timezones with our free online date and time tools.
Epoch Converter – Convert epoch to date and date to epoch with our free online tool.
Time / Stopwatch / Timer / Alarm – Track time, set alarms, use a stopwatch, and manage timers.

Image, Media & Design

Images, QR codes and recording

Audio Recorder – Record your Audio
Code Screenshot – Turn code snippets into beautiful shareable images in your browser: 39 languages, 10 colour themes, gradients, window chrome, line numbers, PNG/SVG export.
Color picker – Pick your desired color
Color Tools – Convert HEX, RGB, HSL, CMYK, Lab and OKLCH colours, check WCAG and APCA contrast, generate Tailwind-style palettes, CSS gradients, box shadows and border radii, and extract a palette from any image.
Crop Image – Free online tool to crop your images
CSS Generators – Free CSS generators with live preview: box shadow, gradient, glassmorphism, clip-path, transform, flexbox, grid, cubic-bezier, scrollbar. Copy CSS or Tailwind.
Exif Cleaner – Clean Exif data from your image
EXIF viewer – View EXIF data and various other metadata of images with our free online tool.
File Type Identifier – Identify the type of the uploaded file
Image Converter, Compressor & Resizer – Convert, compress and resize images in your browser: PNG to WebP, JPG to PNG, SVG to PNG, image to Base64 and back, favicon generator with favicon.ico. Batch convert and download as ZIP. Files never leave your device.
PDF Toolkit – Merge, split, reorder, rotate and delete PDF pages, convert images to PDF and PDF pages to PNG or JPEG, add page numbers or a watermark and edit metadata, all in your browser.
Photo & Video Recorder – Capture screenshots and record videos with audio using your webcam and microphone effortlessly with our free online tool. Ideal for creators and developers!
QR Code Generate/Decode – Generate and decode QR codes with our free online tool.
Simple Image Editor – Edit your image
SVG Optimizer & Converter – Optimize SVG with SVGO in your browser, see bytes saved, then convert to React/Vue components, data URI, CSS background, symbol sprite or PNG, JPEG and WebP.
WiFi QR – Generate and Download QR Codes to quickly connect to WiFi Networks

Network & Device

IP, CIDR and device information

cURL Converter – Convert a cURL command to JavaScript fetch, axios, Python requests, Go, PHP, Ruby, Java, C#, Rust or PowerShell code, or turn a fetch() call back into cURL.
List / Check IPv4 CIDR – List or check ip addresses in the CIDR block
My Device Info – Free tool to get device resolution, browser resolution, aspect ratio, operating system, etc. Helps understand display configurations and optimize the visual configs
See My IP – Show your IP information

Nepal

Bikram Sambat dates, Nepali text, numbers and data

Nepal Address Data – Browse and export all 7 provinces, 77 districts, 753 local levels and 6,743 wards of Nepal in English and Nepali as JSON, CSV, TypeScript, SQL or enum. Free developer tool for Nepali address forms.
Nepali Date Converter (BS ↔ AD) – Free Nepali date converter: convert Bikram Sambat (BS) to AD and AD to BS instantly, see today's date in Nepal, calculate age and date differences, batch convert lists and browse a BS month calendar.
Nepali Font Converter – Convert Preeti, Kantipur and PCS Nepali legacy font text to Unicode Nepali, convert Unicode back to Preeti, or type romanized Nepali to get Unicode Devanagari. Free and instant, right in your browser.
Nepali Number & Currency Tools – Convert numbers to words in Nepali and English (lakh, crore, rupees and paisa for cheques), swap Devanagari and ASCII digits, format amounts in 12,34,567 style and calculate 13% VAT in Nepal with our free online tool.