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Comprehensive CRM platform for customer-facing teams.

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Simple CRM for small businesses moving from spreadsheets.

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Build online forms for every business need.

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Live chat app to engage and convert website visitors.

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Appointment scheduling app for consultations with customers.

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Digital signature app for businesses.

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Comprehensive sales map visualization and optimal route planning solution.

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Complete loyalty and affiliate management platform.

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Cloud Contact Center Software for businesses.

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All-in-one social media management software.

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Create, send, and track targeted email campaigns that drive sales.

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Build online forms for every business need.

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Design surveys to reach and interact with your audience.

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Online website builder with extensive customisation options.

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Website conversion optimization and personalisation platform.

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End-to-end event management software.

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Webinar platform for webcasting online webinars.

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All-in-one marketing automation software.

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Smart landing page builder to increase conversion rates

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Manage all your local business listings on a single platform.

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Live chat app to engage and convert website visitors.

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Digital signature app for businesses.

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Complete loyalty and affiliate management platform.

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Cloud Contact Center Software for businesses.

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Sync, manage, and convert leads across channels seamlessly.

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Online community platform for individuals and businesses to grow their network and brand.

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Unified marketing platform for marketing teams.

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eCommerce platform to manage and market your online store.

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Helpdesk software to deliver great customer support.

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Remote support and unattended remote access software.

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Interactive remote assistance software with augmented reality.

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End-to-end field service management platform for service businesses.

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Live chat app to engage and convert website visitors.

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Voice

Cloud Contact Center Software for businesses.

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The all-in-one toolkit for solopreneurs.

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Appointment scheduling app for consultations with customers.

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Unified platform for customer service and support teams.

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Books

Powerful accounting platform for growing businesses.

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100% Free invoicing solution.

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Expense

Effortless expense reporting platform.

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Powerful stock management and inventory control software.

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End-to-end billing solution for your business.

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Checkout

Collect payments online with custom branded pages.

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Payroll

Payroll software with automated tax payments and filing.

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Solo

The all-in-one toolkit for solopreneurs.

Solo
 
Practice

Practice management software for accounting firms.

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Sign

Digital signature app for businesses.

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eCommerce platform to manage and market your online store.

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Finance Plus

All-in-one suite to manage your operations and finances.

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Mail

Secure email service for teams of all sizes.

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Online meeting software for all your video conferencing & webinar needs.

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Word processor for focused writing and discussions.

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Sheet

Spreadsheet software for collaborative teams.

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Create, edit, and share slides with a sleek presentation app.

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Beautiful home for all your notes.

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Cliq

Stay in touch with teams no matter where you are.

Cliq
 
Connect

Employee experience platform to communicate, engage, and build positive employee relations.

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Bookings

Appointment scheduling app for consultations with customers.

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TeamInbox

Shared inboxes for teams.

TeamInbox
 
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Online file management for teams.

WorkDrive
 
Sign

Digital signature app for businesses.

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Office Suite

Powerful collaborative work platform for teams.

Office Suite
 
Office Integrator

Built in document editors for web apps.

Office Integrator
 
ZeptoMail

Secure and reliable transactional email sending service.

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Calendar

Online business calendar to manage events and schedule appointments.

Calendar
 
Learn

Knowledge and learning management platform.

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Voice

Cloud Contact Center Software for businesses.

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Collaborative task management for individuals and teams.

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Tables

Work management tool to connect people, processes, and information.

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Collaborative online PDF editing tool.

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Workplace

Application suite built to improve team productivity and collaboration.

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People

Organize, automate, and simplify your HR processes.

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Intuitive recruiting platform built to provide hiring solutions.

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Effortless expense reporting platform.

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Workerly

Manage temporary staffing with an employee scheduling solution.

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Payroll software with automated tax payments and filing.

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Employee scheduling and time tracking app.

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Digital signature app for businesses.

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Comprehensive HR platform for seamless employee experiences.

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Security and IT Management

 
Creator

Build custom apps to simplify business processes.

Creator
 
Directory

Workforce identity and access management solution for cloud businesses.

Directory
 
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OneAuth

Secure multi-factor authenticator (MFA) for all your online accounts.

OneAuth
 
Vault

Online password manager for teams.

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Catalyst

Pro-code platform to build and deploy your apps.

Catalyst
 
Toolkit

Complete resource for any admin-related lookup queries.

Toolkit
 
Lens

Interactive remote assistance software with augmented reality.

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Assist

Remote support and unattended remote access software.

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QEngine

Test automation software to build, manage, execute, and report testcases.

QEngine

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Analytics

Modern self-service BI and analytics platform.

Analytics
 
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Embedded analytics and white label BI solutions, tailored for your needs.

Embedded BI
 
DataPrep

AI-powered data preparation service for your data-driven organization.

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Harnessing IoT analytics for real-time operational intelligence.

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Projects

Manage, track, and collaborate on projects with teams.

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Planning and tracking tool for scrum teams.

Sprints
 
BugTracker

Automatic bug tracking software for managing bugs.

BugTracker
 
Solo

The all-in-one toolkit for solopreneurs.

Solo

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Creator

Build custom apps to simplify business processes.

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Flow

Automate business workflows by creating smart integrations.

Flow
 
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Pro-code platform to build and deploy your apps.

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Built in document editors for web apps.

Office Integrator
 
ZeptoMail

Secure and reliable transactional email sending service.

ZeptoMail
 
QEngine

Test automation software to build, manage, execute, and report testcases.

QEngine
 
Tables

Work management tool to connect people, processes, and information.

Tables
 
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RPA

Automate manual, tedious, and repetitive tasks easily.

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Apptics

Application analytics for all apps.

Apptics
 
Embedded BI

Embedded analytics and white label BI solutions, tailored for your needs.

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Build, deploy, and scale IoT solutions for connected businesses.

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AI-powered data preparation service for your data-driven organization.

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Low-code IoT platform and solutions for connected businesses.

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CRM Plus

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Application suite built to improve team productivity and collaboration.

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All-in-one suite

Zoho One

The Operating System for Business

Run your entire business on Zoho with our unified cloud software, designed to help you break down silos between departments and increase organizational efficiency.

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Zoho One
Zoho Marketplace

With over 2000 ready-to-use extensions across 40+ categories, connect your favorite business tools with the Zoho products you already use.

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Port Checker

Discover and run diagnostic checks on your ports with the port checker tool.

Port checker

A port checker is a free, simple-to-use online checker tool that lets you find whether the ports in your computer are open or not. A port is an entity in the computer through which the exchange of information between multiple programs takes place. To understand the capability of the port for forwarding and receiving communications, the status of the port needs to be identified as open or closed. A port checker can also be used to check for vulnerabilities by finding if any open port is left unused.

Ports, along with IP address details, provide vital information about the system when it makes a request. Ports range from 0 to 65,536 out of which 0 to 1,023 are said to be well-known ports. These are some port numbers that are used for specific purposes.

What are well-known and registered ports?

Well-known ports are port numbers that are commonly used for everyday protocols, such as FTP, HTTPS, and IMAP, to name a few. The well-known port 25 is used for SMTP, 80 is used for HTTP, and so on. Registered ports are the port numbers of certain slots that are pre-booked by a client on a temporary basis. The pre-booking is usually done to conduct specific actions for their internal or personal use. Registered ports are also called ephemeral ports because they function for a short time.

Here are some of the commonly used ports numbers

The Internet Assigned Numbers Authority (IANA) reserved ports 0 to 1,023 for standard activities such as:

Port NumberProtocols
80HTTP
443HTTPS
21FTP
143IMAP
110POP3
25SMTP

What happens when a port checker starts its scanning process?

A port checker sends a packet of data to a specific port that the user has looked up, and returns its status. One of the following three possibilities can happen:

  • The port could be open and ready to listen.
  • The port could be closed (i.e., currently in use) and not ready to listen.
  • The port could be silent, which indicates that it can be blocked, dropped, or filtered.

What are TCP and UDP ports?

TCP and UDP are the most commonly used protocols in computer networks for data transmission. A port checker follows either of the two protocols while transmitting packets through the network. Transmission Control Protocol (TCP) is more reliable because it provides a three-way handshake for establishing a secure connection between the sender and the receiver, and the packets are transmitted in order. User Datagram Packet (UDP), on the other hand, is faster and not as reliable as the TCP because they lag in error checking. These types of transmissions are often seen in live streaming and online gaming.

Port scanning techniques

There are multiple ways in which port scanning can be done. Some of the most common techniques are:

  1. Ping scan: A ping scan is the simplest technique of all. It sends a data packet as a ping request and checks the status of its port.
  2. SYN scan: A SYN, or half-open TCP scan, is a one-way handshake method. The checkers initiate a TCP connection and can identify if the port is open with the help of an ACK message. In this technique, the TCP connection is not fully established.
  3. TCP scan: A traditional three-way handshake takes place. It is as same as a SYN scan, but the full connection is established, unlike the half-open TCP scan.

What is a port scan attack?

Attackers can use this same port checker to inspect which port can be targeted because of a vulnerability. Usually ports that are open and unused for a long time can be a loophole for attackers to invade, as the open status helps attackers take control over the ports easily—even to destroy the application.

How a port check helps with security

Because a port scan attack happens mostly on an organization level, a business must ensure that it has a well-wrapped firewall, a private authorized access, and periodical checks on its unused network holes.

Frequently Asked Questions

  • What is the importance of port scanning?

    Scanning a port can get all sorts of vital information about the target system, and at the same time you will know which ports are currently open and which ones are at work.
  • How do I check if my ports are open?

    With the help of Zoho Toolkit's port checker, you can easily check whether a particular port in the system is open or closed. Simply enter the domain name and its port number and hit enter. The port checker will automatically update you with the status of that particular port.
  • Where do I check what port numbers are in use?

    With the help of the Terminal or Command prompt, you can easily find the port number that your system is using at moment. For windows, use netstat - a; for Mac, use netstat - an. This lists out all of your ports.

  • How do I close an unused open port?

    An unused open port can be closed in two different ways: You can permanently disable the service, or you can use a firewall to take proper measures. If you choose the first step, understand that the impact can be the port being permanently shut, and you won't be able to use it even after a reboot.