Sideline
Your Phone's Other Number
Sideline is a mobile app that provides a second phone number on an existing device, keeping a personal number private while supporting separate calling, texting, and voicemail. It connects through the carrier's network rather than requiring WiFi, and it can label unknown callers and texters to help identify spam and potential fraud.
Core capabilities include number selection and porting, unlimited SMS and MMS, group messaging, custom caller ID, separate voicemail with transcription, and optional WiFi calling. Auto-Reply can respond to missed calls or inbound texts, with customizable content, branded messages, signatures, and links. Ring and text tones help distinguish the second number. The app is available for iOS and Android, with web messaging listed as a product area.
12 alternatives to Sideline
Ranked by how well each tool replaces Sideline: shared features, audience, price and popularity.
A second phone number on your existing phone for privacy and small business use.
59 out of 100 match$7.99/mo- 58 out of 100 matchContact sales
Identify unknown callers, block spam calls and messages, and protect against fraud
Has a free plan.
Free plan57 out of 100 matchContact sales- 56 out of 100 matchFree
- 54 out of 100 matchFree
Find out who called. Search any number worldwide and identify the caller info
Has a free plan.
Free plan54 out of 100 match$4.17/mo- 54 out of 100 match$9.95/mo