Find and extract duplicate links from HTML code. Free online tool to analyze URLs in HTML source.

Free, fast, and secure donate button generator tool for your everyday needs.

Learn how DNS works and find the IP address of any domain. Generate dig and nslookup commands.

Calculate DNS propagation duration, TTL cache expiration across recursive resolvers, and plan zero-downtime DNS cutover migrations.

Check DNS records for any domain name. View A, AAAA, MX, NS, TXT, CNAME, and SOA records.

Design and analyze Infinite Impulse Response (IIR) digital filters online. Calculate Butterworth, Chebyshev Type I/II, and Elliptic biquad coefficients, pole-zero Z-plane coordinates, and frequency response with bilinear transform.

Compare two texts side by side and find differences instantly. Highlight additions, deletions, and changes. Free online diff tool for code, text, and documents.

Convert decimal numbers to ASCII characters.

Calculate optimal database connection pool sizes for PostgreSQL, MySQL, and HikariCP. Balance max_connections, application CPU threads, and memory overhead.

Calculate McCabe cyclomatic complexity, Halstead software science metrics, Maintainability Index (MI), estimated defect density, and programming effort from code.