Encoder, decoder, and hash generator
Convert text to and from Base64, Base64url, URL, JWT, and hex, and generate MD5, SHA-256, SHA-512, and HMAC signatures. All in your browser.
Encode, decode, or hash text
Everyday encoding and hashing for network engineers
Encoding converts text and binary data into safe transport formats (such as Base64 or URL percent-encoding), while cryptographic hashing produces deterministic, fixed-length fingerprints used to verify data integrity and authenticate API webhooks. Both come up constantly when debugging captive portal redirect parameters, inspecting authentication tokens, or building webhook listeners. This tool executes all transformations locally in your browser, ensuring confidential payloads are never uploaded.
What this tool gives you
- Two-way Base64, URL-safe Base64url, and URL parameter conversion with live error handling and formatting options.
- Captive portal redirect URL parser with one-click presets for Cisco Meraki, Aruba ClearPass, Ruckus SmartZone, and Fortinet.
- Full cryptographic suite including MD5, SHA-1, SHA-256, SHA-512, and HMAC-SHA256 signature calculation with custom secret keys.
Captive portal redirect parameters and URL encoding standards
When a wireless client associates with a guest WiFi network, the access point (AP) or wireless LAN controller (WLC) intercepts the initial HTTP request and issues an HTTP 302 redirect to the external captive portal splash page. To maintain state across the onboarding flow, the controller appends essential hardware and network context to the query string.
1. Cisco Meraki splash parameters
Meraki MR access points pass base_grant_url (the endpoint to authorise the client), user_continue_url (the guest's target URL), node_mac (AP MAC address), and client_mac. Correct percent-encoding of the grant and continue URLs is essential to prevent redirection loops.
2. Aruba ClearPass and Instant AP parameters
Aruba Instant APs and controller-managed architectures pass cmd=login, mac, ip, essid, apname, and url. Nested original destination URLs must be safely decoded when constructing post-login landing pages.
3. Ruckus SmartZone and ZoneDirector parameters
Ruckus controllers forward sip (controller IP), uip (client IP), mac (unformatted or colon-separated MAC), vlan, and url. Our tool detects MAC formats and automatically identifies Ruckus controller redirect structures.
For a complete technical overview of captive portal onboarding protocols, RADIUS authentication, and walled garden configurations, review our comprehensive captive portal technical guide and the RADIUS setup reference guide.
Cryptographic hash functions and webhook signature reference table
Cryptographic hashes produce deterministic, fixed-length digest outputs from arbitrary input data. Unlike encoding (which is fully reversible), cryptographic hashes are one-way functions designed to verify data integrity and authenticate API requests.
| Algorithm | Digest Output Length | Security Status | Primary Application | Standard Specification |
|---|---|---|---|---|
| HMAC-SHA256 | 256 bits (64 hex chars) | Strong (Recommended) | API authentication, webhook signature validation (Purple Webhooks, Stripe) | RFC 2104 / FIPS 198 |
| SHA-256 | 256 bits (64 hex chars) | Strong (Recommended) | TLS certificates, digital signatures, blockchain proof-of-work | FIPS 180-4 / NIST |
| SHA-512 | 512 bits (128 hex chars) | Strong (Recommended) | High-security password hashing (with salt/KDF), data archiving | FIPS 180-4 / NIST |
| SHA-384 | 384 bits (96 hex chars) | Strong (Recommended) | NSA Suite B cryptography, enterprise VPN integrity checks | FIPS 180-4 / NIST |
| SHA-1 | 160 bits (40 hex chars) | Deprecated | Git commit hashes, legacy file integrity checks (insecure for TLS) | RFC 3174 (SHAttered attack 2017) |
| MD5 | 128 bits (32 hex chars) | Insecure / Broken | Legacy non-cryptographic file checksums and Content-MD5 headers | RFC 1321 (Collision vulnerable) |
| CRC32 | 32 bits (8 hex chars) | Non-Cryptographic | Ethernet frame check sequences (FCS), ZIP file archive integrity | IEEE 802.3 |
Understanding the differences: encoding, encryption, and hashing
Encoding (Reversible, No Key)
Transforms data into a format safe for transmission across networks or storage in text systems (e.g. Base64, URL percent-encoding). Anyone can decode encoded data without a secret key. Encoding does not provide confidentiality.
Hashing (One-Way, Deterministic)
Generates a fixed-size fingerprint from input data. It is computationally infeasible to reconstruct the original input from the hash (preimage resistance) or find two inputs with the same hash (collision resistance). Used for integrity checks.
Encryption (Reversible with Key)
Transforms plaintext into ciphertext using a mathematical cipher (e.g. AES-256, RSA) and a cryptographic secret key. Only holders of the decryption key can recover the original data. Provides confidentiality.
Automate guest WiFi onboarding and webhook data delivery
Eliminate manual captive portal scripting. Purple connects natively with Cisco Meraki, Aruba, Ruckus, Fortinet, and Extreme Networks to automate guest authentication, GDPR-compliant data capture, and real-time webhook delivery to your CRM.
Related network engineering tools and technical guides
RADIUS setup guide
Configure FreeRADIUS and Cloud RADIUS servers with Cisco, Aruba, and Ruckus controllers.
SSL certificate checker
Inspect TLS certificates, certificate chains, expiry dates, and SAN extensions for captive portal domains.
MAC address lookup
Identify OUI vendor details, device manufacturers, and randomisation status for connected clients.
Captive portal guide
Comprehensive architectural reference for guest WiFi authentication and compliance.
Frequently asked questions
What is the difference between encoding, encryption, and hashing?
Encoding (such as Base64 or URL encoding) is a reversible transformation designed for safe data transmission; anyone can decode it without a key. Encryption transforms data into ciphertext using a secret cryptographic key, ensuring confidentiality so only authorized key holders can decrypt it. Hashing is a one-way mathematical function that computes a unique fixed-length digest from input data; it cannot be decrypted and is used to verify data integrity.
Why is URL encoding necessary for captive portal redirect parameters?
When a wireless LAN controller (WLC) intercepts an HTTP request to display a splash page, it appends redirect parameters (like original URLs, MAC addresses, and grant endpoints) to the query string. Characters like slashes (/), colons (:), and question marks (?) must be percent-encoded so web browsers and proxy servers do not misinterpret nested parameters as URL delimiters.
How does Base64url differ from standard Base64?
Standard Base64 (RFC 4648) uses plus signs (+) and forward slashes (/), which have special syntactic meaning in URLs and filenames. Base64url (RFC 7515) replaces plus with hyphen (-) and slash with underscore (_), and strips trailing padding equals signs (=), making tokens safe for URL query strings, HTTP headers, and JSON Web Tokens (JWTs).
How do you verify HMAC-SHA256 signatures on API webhooks?
When an external platform (such as Purple, Stripe, or GitHub) sends a webhook event, it generates a hash of the raw HTTP request body using a shared secret key via HMAC-SHA256 and includes it in a signature header. Your server computes the identical HMAC-SHA256 hash using the same secret key and compares the digests using constant-time string comparison to verify authenticity.
Which hash algorithms are safe for network credentials in 2026?
SHA-256, SHA-384, and SHA-512 (SHA-2 family) along with SHA-3 are strongly recommended by NIST for cryptographic integrity and digital signatures. MD5 and SHA-1 have proven mathematical collision vulnerabilities and must never be used for security purposes or password hashing.
Does this tool send any of my tokens, secrets, or URLs to an external server?
No. All encoding, decoding, JSON Web Token parsing, and cryptographic hash computations run 100% locally in your browser using standard JavaScript and the native HTML5 Web Crypto API (crypto.subtle). No payload data is ever transmitted to Purple or third-party servers.
Building captive portals or webhook integrations?
Encoding redirect URLs and validating HMAC webhook signatures is part of every custom WiFi deployment. Purple automates the complete onboarding workflow, data validation, and CRM synchronisation across your entire access point fleet.
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