We build useful tools for anyone who works with or worries about phone calls. No account. No paywall. No nonsense.
// Free tools
All tools are free to use. No signup required. More tools ship regularly.
Number lookup
Check carrier, line type, fraud score, portability and country for any phone number instantly.
E.164 converter
Convert any number between E.164, national, international, and RFC 3966 formats. Works worldwide.
SIP code decoder
Paste any SIP response code and get a plain-English explanation, common causes, and fixes.
DTMF test line
Call our free test number to hear your caller ID, STIR/SHAKEN attestation level, and test your DTMF keypad tones.
Spam score check
Cross-reference any number against public spam and scam databases.
Scam pattern checker
Match a number against known scam patterns — Macau scam, LHDN, Bank Negara impersonation, and more.
Best time to call
Enter a number and get the caller's local timezone and whether it's a reasonable hour.
Country code lookup
Search any country for its dialling prefix, number format rules, and emergency numbers.
VoIP bandwidth calc
Choose a codec and number of concurrent calls — get exact bandwidth needed in Kbps.
MOS score calculator
Enter jitter, latency, and packet loss — get an estimated call quality MOS score.
Community scam board
Submit and search scam numbers reported by the community. Crowdsourced protection.
Bulk number lookup
Upload a CSV of numbers and get carrier and line type data for all of them at once.
Caller ID reputation
Full spam reputation report for any number — history, carrier hops, and community reports.
// Sazrika Learn
Interactive animated diagrams — no jargon, no RFC documents. Just step-by-step visuals.
Sazrika Foundation exists to make telephony knowledge and tools accessible to everyone. Whether you're checking a suspicious number, debugging a SIP trunk, or just curious how your phone call works — these tools are here, free, no strings attached.