UD5 Toolkit
Base64 String Validator - Online Check Valid Encoding
Paste a string and verify if it is valid Base64. Auto‑detects padding issues and character errors. Quick dev check.
Crypto Address Format Checker - Online Validate Wallet
Crypto Address Format Checker
Instantly validate wallet address formats for 10+ cryptocurrencies
Try a sampleBitcoin
1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa3J98t1WpEZ73CNmQviecrnyiWrnqRhWNLyFrequently Asked Questions
It validates the format of cryptocurrency addresses including length, character set, and basic checksum patterns. For Bitcoin, it distinguishes between Legacy (P2PKH), SegWit (P2SH), and Bech32 formats. For Ethereum/BNB, it checks the 0x prefix and hex structure. It does not check if the address is active or contains funds.
BTC, ETH, BNB (BSC), LTC, BCH, DOGE, XRP, TRX, SOL. More chains are added regularly. Each coin is validated against its unique address rules (Base58, Bech32, Hex, etc.).
You may have selected the wrong coin. Also, some newer address types (like Taproot for Bitcoin) might not be recognized yet. Ensure there are no extra spaces and the address is exactly as copied from your wallet.
A checksum is a short code derived from the address data that helps detect typing errors. For example, Bitcoin uses a double SHA-256 checksum at the end of its Base58-encoded address. If you mistype one character, the checksum will likely mismatch, making the address invalid.
No, this checker only validates raw hexadecimal Ethereum addresses (0x...). It does not resolve ENS domain names.
Absolutely! All validation happens in your browser. No data is sent anywhere. You can even save the page and use it without internet.
DNSSEC Chain Validator - Online Check RRSIG & DS
Validate a DNSSEC chain by entering DS and RRSIG records. Verify that signatures match. Educational. Local algorithm.
SSL Certificate Checker - Online Verify Expiry & Chain
Enter a domain and see its SSL certificate details: issuer, validity dates, and chain. Client‑side fetch.
SSL Certificate Checker - Online TLS Expiry & Info Tool
Inspect any website's SSL/TLS certificate details: issuer, expiry date, subject, and SANs. Verify certificate chains. All checks are private and require no server upload.
SSL Cipher Suite Checker - Online Test TLS Security
Check which cipher suites a website supports and identify weak or outdated ones. Quick security audit from your browser.
Advanced Number Base Converter - Online Bin Oct Dec Hex Custom
Convert numbers between binary, octal, decimal, hex, and any custom base up to 36. With live preview of all bases.
UTF‑8 to Base64 Converter - Online Encode Text
Encode any text, including emojis and foreign scripts, into a Base64 string. Perfect for data URLs. Local.
Base64 to UTF‑8 Converter - Online Decode Text
Decode a Base64 encoded string that contains UTF‑8 text (emojis, international characters). See the raw output. Local.
Email Header Analyzer - Online SPF, DKIM, DMARC Check
Paste raw email headers and see authentication results (SPF, DKIM, DMARC) in a readable table. Find spoofing attempts.
JSON‑LD to Turtle Converter - Online RDF Format
Convert JSON‑LD structured data into Turtle (TTL) notation. For semantic web and linked data developers. Client‑side.
Semaphore Flag Translator - Online Signal Code Converter
Translate text into semaphore flag positions and decode semaphore back to letters. Interactive animated flags. For scouts and maritime fans.
Audio/Video Sync Tester - Online Lip Sync Check
Load a video and visually check if audio aligns with lips. Use frame‑by‑frame stepping. Debug playback issues.
English Text to IPA Converter - Online Phonetic Transcription
Convert English words into their International Phonetic Alphabet (IPA) representation. For pronunciation learning. Local.
Beat Sync Tester - Online Tap Tempo & BPM Counter
Tap any key to the beat and get the BPM (beats per minute). Useful for DJs, musicians, and running. Simple and accurate.
Audio Format Converter - Online MP3 WAV FLAC OGG
Change audio files between MP3, WAV, FLAC, and OGG. Choose codec and bitrate. Works completely offline in the browser.
Drum Pattern Sequencer - Online Create Beats & Play
Lay down a beat on a grid sequencer for kick, snare, and hi-hat. Play, loop, and adjust tempo. All sound via Web Audio API.
File to Base64 Encoder/Decoder - Online Download
Encode any file into a Base64 string that you can copy, or decode a Base64 string back to a downloadable file. Pure frontend.
WAV to MP3 Converter - Online Audio Compression
Convert WAV audio files to MP3 directly in your browser using a built‑in codec. Choose bitrate and quality. No upload.
Visual Stress Pattern Checker – Online See Effect
Display striped patterns that can cause visual distortion. Learn about visual stress. Switch colors.
Sleep Debt Tracker - Online Cumulative Sleep Loss Calculator
Log daily sleep to see cumulative sleep debt or surplus over weeks. Visualizes chronic sleep loss trends. Stores data locally in your browser only.
Sleep Log Tracker - Online Record Hours & Quality
Log the hours you slept each night and rate the quality. See a weekly bar chart. Local storage.
Flame Test Colors - Online Element Identification Chart
Click a metal ion to see the characteristic flame color and wavelength. Useful for analytical chemistry reference.
Tea Steeping Timer - Online Perfect Brew Countdown
Choose your tea type and start a precise steeping timer with color‑changing background. Never over‑steep again.
Online Audio Compressor - Reduce Dynamic Range
Apply compression and limiting to an audio file with threshold, ratio, attack, and release controls. Improve loudness. All local.
Simple Time Tracker - Online Project & Task Hours Logger
Start/stop timer per project to log hours. See daily and weekly totals. Data stays in localStorage. Export summary as CSV. No account needed.
Sting Reaction Tracker – Online Measure & Log Redness
Use a coin for scale and log the size of swelling after an insect sting over time. Detect allergic progression.
Habit Streak Counter - Online Daily Check-in & Chain Visualizer
Track up to 5 habits with a visual chain. Tap to mark day as done, see longest streaks. Data saved in your browser. Inspired by 'Don't break the chain' method.
4‑7‑8 Breathing Technique Timer – Relaxation Exercise
Follow an animated circle that guides you through the 4‑7‑8 breathing pattern. Inhale 4s, hold 7s, exhale 8s. Counts cycles and provides haptic cues.
Time Until Retirement Clock - Online Countdown to Freedom
Set your desired retirement date and see a live countdown of remaining days, hours, minutes. Totally motivating.
UI Animation Timing Demo - Online Easing Presets
Compare all CSS easing presets side by side on a bouncing ball. See which curve fits your UI animation.