Data Sync - Getting Started

Introduction

Byteline allows users to synchronize data of two different databases or CMS systems with ease. Whether you want to keep the data of two CMS systems synchronized or want to ensure your databases are synchronized, the platform lets you do it effortlessly. 

How to Sync Data between two applications

In this guide, we have uncovered a few simple steps to help you synchronize data between two applications, namely Airtable and Webflow, using Byteline. These instructions are applicable for any two CMS systems or databases.

We have divided this article into four sections to make it easy for you to understand the process of data synchronization on Byteline, as illustrated below:

1. Configuring Data Sync
2. Handling Existing Data
3. Preview
4. Start Sync
5. View Records Sync History

Let’s begin. 

Configuring Data Sync

In this section, you will learn how to configure two applications, Airtable and Webflow, for data synchronization between them with Byteline. 

Select Apps

To configure data synchronization, you first need to select two different applications, which can be done by following the steps mentioned below. 

Step 1: On the New Sync page, click on the Add New button next to the My Syncs in the sidebar menu. 

Step 2: Click on the "Pick first app to sync" field and select the your app from the dropdown list. 

Step 3: Sign in to Airtable by clicking the Sign in button next to the dropdown. 

Step 4: Once you have signed into Airtable, select the desired base from the Airtable base dropdown list. 

Step 5: Click on the "Pick second app to sync" dropdown and select Webflow from the dropdown list. Now, create a connection to Webflow like how you did for Airtable

Step 7: Once you have signed into Webflow, select the "object type" along with the Site from the dropdowns. 

Step 8: Click on the Save & Proceed button.

Select Table(s)

Step 1: Once you select the Airtable base and Webflow site, you can view available tables for both. Choose the desired table from Airtable and Webflow dropdown list. Byteline performs mapping automatically based on the table names.

Step 2: After selecting the desired table(s) from Airtable and Webflow, delete all other tables displayed on the screen by clicking on the Trash Bin button. 

Note: Users can synchronize the data either two-way or one-way. By default, the sync is set to two-way. You can set the sync one way, either left to right or right to left.     

• Two-way sync: In this type of sync, the data is synchronized bidirectionally whether you create, update, or delete in the Airtable or Webflow. 
• One-way sync: In this type of sync, the data is synchronized only in one direction, right-to-left or left-to-right. 

Step 3:  Click on the Save & Proceed button.

Filters

In the table mapping screen, you can configure filter(s) on one or both sides of the sync. The filter only affects the data consumed from the side of the sync where it's configured. For example, if you add a filter on Airtable (above sync) to filter out the records with the empty "Name" field, then it will only sync the Airtable records with some value in the "name" field. It will not have any effect on the records read or created/updated on the Webflow.

Below is a sample filter on the Airtable "Name" field.

Date & Time Filters

Byteline offers robust filtering options, including support for date and time-based filters. These filters can handle both absolute date-times, such as 2020-10-26T16:56, and relative formats like -30d (for the past 30 days). For a detailed guide on using date and time formats in filters, visit our documentation on writing dates.

Selecting Data To Sync

When setting up your sync, you can choose from three options to determine which data should be synchronized.

Both Existing and Future Data

This option ensures that all your data—both past and future—remains in sync. It works in two stages:

• Historical Sync: All existing data is synced.
• Ongoing Sync: Once the sync is live, it continuously updates with new changes.

Choose this option if you want a fully synchronized dataset that includes historical data and stays up to date with future changes.

Existing Data Only

This option syncs only the existing data at the time of execution. It does not keep syncing new changes after the initial run.

• Ideal for one-time syncs.
• You can manually rerun the sync whenever needed.

Use this if you only need a snapshot of your current data without keeping the sync always running.

Future Data Only

This option starts syncing only new data changes from the moment the sync goes live. Any existing data before the sync starts is ignored.

Note: Since past data is not synced, only records that change after the sync starts will be in sync. Older records may remain out of sync.

Choose this option if you only need to track new and updated records going forward.

Configure Field Mapping

Once you select the tables, you need to configure the field mapping for both applications in the Byteline console by following the below steps. Byteline performs mapping automatically based on the field names.

Be sure to map all required fields, indicated by the "Required" tag next to each field.

Field-Level Sync Direction

Byteline supports field-level sync direction for ongoing data sync, giving you detailed control over how data moves between systems.

With the blue direction buttons, you can easily set different sync directions for individual fields, ensuring data flows exactly where it’s needed. This feature helps you customize and optimize your sync process for greater flexibility and accuracy.

Generated or Read-only Fields

Every cloud app has read-only fields that can't be changed but can be read; these include record IDs, formulas, etc. These fields can only be the source of the sync. In other words, you can't update the value of a read-only field by taking value from the other app.

When you select a read-only field for the mapping and then select the mapped field from the other app, the icon in the center will change to indicate a one-way sync with the source being the chosen read-only field.

Below is an example of the "ID" field from Notion mapped to a "Notion ID" field in Airtable. When a new record is created in Notion (left), its ID will be sent to Airtable's "Notion ID" field. But if you manually change the "Notion ID" in Airtable, the change will not be synced.

Mapping One Field to Multiple Fields

You can map one field to multiple fields in the connected app. This is helpful when the same information needs to be used in more than one place.

For example, you can map a Title field to:

• A Title field in your CMS
• A Slug field used for the page’s web address

This lets the same source title provide values for both fields.

Another example is an Email Address field. One email address can be sent to multiple connected fields, helping you keep contact information consistent across your systems.

Mapping rules

• One field can send its value to multiple fields.
• Only one of those mappings can be two-way.
• Any additional mappings from that field must be one-way.
• A receiving field can have only one source field.

For example, Title ↔ Title can be a two-way mapping, while Title → Slug is a one-way mapping.

These rules prevent conflicting updates while allowing you to reuse the same information across multiple fields.

Syncing Multilingual Content?

If your source app stores content in separate language fields (for example: Title_EN, Title_FR, Title_DE), you can map each field normally during sync.

See Multilingual Content Support for full details.

Existing Data

Byteline allows you to sync your existing data for the tables configured for the sync. Simply choose the direction in which the data should be synced by selecting one of the arrow buttons on the screen below.

Once the direction is selected, click the "Save & Proceed" button to continue.

For details on the syncing existing data, check out our Historical Sync documentation.

Preview (for existing data)

On the next screen, you'll see a preview with a summary of the records that will be impacted for each table. This includes the number of records that will be created, updated, and deleted for the selected CMS systems.

Records to be deleted

When syncing existing data, some records may be marked for deletion. Byteline gives you the ability to review these records in advance, providing peace of mind by ensuring that only expected records are deleted.

To view the details of these records, click the red-underlined link for each "Will delete items" value. This will open a pop-up displaying the records to be deleted in a table format.

You can also export these records as a CSV file for backup purposes.

When no existing records can be matched

Sometimes Byteline cannot confidently match records that already exist in both apps. For example, you may have 200 contacts in one app and 10 customers in another app, but none of them share the same matching values.

When this happens, Byteline will ask you how you want to continue:

Add records as new Choose this if you want to keep the existing records in the destination app. Byteline will create the source records as new records. This is the fastest option, but it may create duplicates if some records already exist in the destination app.

Clear the destination app first Choose this if you want a clean import with no duplicates. Remove the existing records directly in the destination app, then return to Byteline and check again.

Byteline does not remove existing destination records for you during this step. Existing records stay unchanged unless you remove them in the destination app.

Start Sync

After you're satisfied with the Preview results, click on the Start Sync button. 

Once the synchronization is complete, a message will appear on the screen saying, Historical data sync completed successfully! and Sync successfully turned live! Changes will actively sync. After a few seconds, you will be automatically redirected to the Change History page. 

View Records Sync History

Byteline allows the users to view the record-level history of all the data synchronization made between CMS systems with ease. 

On the Change History page, you can view the history of any of the changes made in both Airtable or Webflow. For example, if you make any change in one of the CMS systems, it will be automatically reflected on the other system that you have connected for data synchronization.

In this case, whether you make any changes in Airtable or Webflow, it automatically changes in the other one. You do not need to make changes in both tables manually. 

Field Mapping Rules

Handling multiple values mapped to a single field

If a source field (such as phone numbers or emails) contains multiple values, and you map it to a single-value field on the destination, Byteline will sync only one value.

– When the source has a “primary” value (e.g., primary phone), the primary is used.

– If no primary is defined, the first value in the list is used.

This ensures predictable results for your syncs.

How empty field values are handled

Byteline handles empty field values differently when creating a new record versus updating an existing record.

When Byteline creates a new record in the destination app, empty source fields are skipped by default. This means Byteline does not send empty values just to clear or overwrite fields in the destination app.

This helps protect default values, required setup, or app-specific behavior in the destination app.

For example, if a source record has a name but its description is empty, Byteline will create the destination record with the name and leave the description field untouched.

Source record:
Name: Blue Shirt
Description: empty

Destination record created:
Name: Blue Shirt
Description: left unchanged or handled by the destination app

After a record has already been created or matched, mapped fields stay in sync. If a user later clears a mapped field in the source app, Byteline will also clear the corresponding field in the destination app.

For example:

Before update:
Source Description: Lightweight cotton shirt
Destination Description: Lightweight cotton shirt

User clears Description in the source app.

After sync:
Source Description: empty
Destination Description: empty

This behavior keeps synced records accurate while avoiding unwanted overwrites during record creation.

Important: Byteline only clears a destination field when the source field is clearly emptied. If a field is missing from an app response, unavailable, or not included in the sync, Byteline does not treat that as a cleared value.

Understanding Sync Issues

When Byteline syncs your data between two apps, it occasionally runs into something it can't complete on its own — for example, a required field is empty, an app rejects a value, or a connection needs to be reauthorized. Instead of burying you in hundreds of individual record errors, Byteline groups these into a small number of clear, actionable Sync Issues.

Think of a Sync Issue as a single, plain-English summary of one problem, along with the list of records it's affecting and, where possible, a one-click button to fix it.

How sync issues are created

As your sync runs, any record that can't be synced generates an error or a warning. Rather than showing each one separately, Byteline rolls related errors up into a single issue so it's easy to understand and fix.

The grouping is smart — errors are combined by what actually caused them, for example:

• One issue per problem type — e.g. "A connection has expired" appears once, not once per record.
• One issue per field — e.g. all records failing because of the same field mapping are grouped together.
• One issue per specific value — e.g. if a dropdown option is missing in your target app, each missing option becomes its own issue (so "Add the 'Marketing' option" is separate from "Add the 'Sales' option").
• One issue per record — for problems that are genuinely specific to a single record.

Each issue shows:

• A short description of what went wrong and how to fix it.
• Whether it's an Error (sync is blocked for those records) or a Warning (records synced, but something needs your attention).
• The number of affected records, and the list of those records.

As the same problem recurs, Byteline keeps adding the newly affected records to the same issue and updates the count — so the issue list stays short and meaningful.

Sync issues can resolve themselves automatically

Most issues need you to take action to fix them — but some clear on their own once the underlying cause is resolved, so you won't have to chase down every record manually. Here's when an issue resolves automatically:

• When affected records sync successfully. Byteline watches your ongoing syncs. As each affected record syncs cleanly, it's removed from the issue. Once every affected record has synced successfully, the issue is automatically marked as Resolved.
• When you reconnect an app. Issues caused by an expired connection or missing permissions resolve automatically after you reconnect the affected app.
• When you upgrade your plan. Issues caused by reaching a plan's sync limit resolve automatically once you're on a higher plan.

Good to know: An affected record is cleared only when that specific record syncs again cleanly. If a record that previously failed doesn't change again, it won't re-sync on its own — so an issue can keep showing older affected records until those records are re-synced or you resolve the issue manually. If you've fixed the root cause and just want the issue gone, you can mark it as Resolved yourself.

One-click fixes

Wherever Byteline can fix a problem for you, the issue includes an action button so you don't have to leave the app or edit anything by hand.

A common example is a missing dropdown/select option in your target app. When a value coming from the source app doesn't exist as an option in the target field, you'll see a button like:

Add 'Marketing' option and retry 12 records

Clicking it does both steps for you:

1. Adds the missing option (in this example, "Marketing") to the field in your target app.
2. Retries the affected records so they sync with the newly added option.

Other issues offer similar helpers depending on the problem — for example, reconnecting an app, adjusting a field mapping, or marking an issue as resolved once you've fixed it elsewhere. You'll only see the buttons that make sense for that particular issue.

Email notifications

Byteline emails you about open issues so you don't have to keep checking the dashboard — but it batches them so you're never spammed:

• Errors: at most one email every 12 hours. (When a fresh batch of errors starts, Byteline waits a short time to collect related errors before sending, so you get one useful summary rather than a flood.)
• Warnings: at most one email every 24 hours, since warnings are less urgent.

Each email summarizes the pending issues for your sync, so you can jump straight in and resolve them.