Weld is a Copenhagen-based, cloud-only data platform that bundles ELT, SQL transformations and reverse ETL, priced on Monthly Active Rows with plans from $99 a month. Airbyte is a data movement platform with 700+ prebuilt connectors that load SaaS, API and database data into any destination, with a free self-hosted edition, cloud plans from $20 a month, and hybrid or on-prem deployment. Weld is designed as an all-in-one tool for lean analytics teams, especially in e-commerce and marketing; Airbyte is designed to be the data movement layer of a modular stack. The practical differences come down to connector coverage, how Weld's plans gate features like CDC and sync frequency, and where your pipelines can run.
Airbyte vs Weld at a glance
| Airbyte | Weld |
|---|
| Category | Data movement (ELT and CDC) platform | All-in-one ELT, SQL transformation and reverse ETL platform |
| Company | Open-source project launched in 2020 | Founded in Copenhagen in 2021; $4.6M seed led by Frontline Ventures and Cherry Ventures |
| Prebuilt connectors | 700+, including SaaS APIs, databases, files and unstructured sources | Weld-built connectors, strongest in marketing, e-commerce and SaaS apps |
| Custom connectors | No-code Connector Builder with AI assist, low-code CDK, Python CDK | Python custom connectors you host yourself (Premium and above) |
| Pricing model | Volume-based (Standard, Plus) or capacity-based Data Workers (Pro, Enterprise Flex) | Monthly Active Rows, with caps on connector types and users per plan |
| Entry price | Free (Core); $20/month (Standard) | $99/month (Basic, billed yearly): 2 connectors, 1 user, 5M MAR, daily syncs |
| Change data capture | Log-based CDC on every plan | +$479/month on Business; included on Enterprise; not available on Basic or Premium |
| Sync frequency | Scheduled per connection; CDC keeps databases near real time on every plan | Tied to plan: daily on Basic, hourly on Premium, 15-minute on Business, 5-minute on Enterprise |
| Transformation | Native dbt, Airflow, Dagster and Prefect integrations; you choose | Built-in SQL editor with AI assistant; dbt integration from Premium |
| Reverse ETL | Supported | Included on all plans |
| Deployment | Self-hosted (Core), managed cloud, hybrid or on-prem (Enterprise Flex) on one codebase | Cloud-only SaaS; choice of AWS, GCP or Azure on Enterprise |
| Python and API access | PyAirbyte, Airbyte API, Terraform provider | Weld Connect REST API and MCP server (Premium and above) |
| Security and compliance | SOC 2, ISO 27001, GDPR, HIPAA conduit | SOC 2 Type II, GDPR |
| Open source | Yes | No |
| Community | 25,000+ members, 1,000+ contributors | Vendor-led |
About Airbyte
Airbyte is the open standard for data movement, used by 18% of the Fortune 500. It replicates data from 700+ sources into warehouses, lakehouses, databases and AI context stores, and runs self-hosted, fully managed, or hybrid inside your own boundary.
About Weld
Weld was founded in Copenhagen in January 2021 by Jonas Thordal, Jakob Skytte and Jakob Kristensen, former employees of the fintech Pleo. Later that year it raised a $4.6M seed round led by Frontline Ventures and Cherry Ventures, with angels including Intercom co-founder Des Traynor. Weld sells an all-in-one platform: managed ELT connectors, a SQL editor with an AI assistant called Ed, data lineage, orchestration and reverse ETL. More recently it has added the Weld Connect API, an MCP server for AI agents, and forward-deployed engineers to help customers build agent workflows.
Pricing: MAR plans with feature gates vs. capacity
Weld prices on Monthly Active Rows (MAR), the rows inserted or updated in your destination each month, and each plan also caps connector types and users:
- Basic: $99/month, billed yearly. 5M MAR, 2 connector types, 1 user, daily syncs and 1 destination. Extra connectors cost $49/month each (up to 2 more), and 6-hour syncs are a $99/month add-on.
- Premium: $389/month. 10M MAR, 6 connector types, 3 users and hourly syncs. Adds dbt integration, orchestration, custom connectors, the Weld Connect API and the MCP server.
- Business: $959/month. 50M MAR, 10 connector types, 5 users, 15-minute syncs and multiple destinations. CDC is a $479/month add-on, and 5-minute syncs cost another $99/month.
- Enterprise: quote-based. Custom volumes and connector limits, 5-minute syncs, CDC included, and a choice of AWS, GCP or Azure.
Weld counts only unique connector types, so several Shopify stores use one connector slot, and it doesn't charge for a new connector's first 14 days, the first sync of a new table, or backfills requested through support. But costs still move with three dials at once: how many rows change, how many connector types you add ($49–$99/month each beyond the plan), and how fresh you need the data. A team on Business that needs CDC pays $959 plus $479, about $1,440 a month, before extra connectors or MAR.
Airbyte Core is free to self-host. Cloud starts at $20/month (Standard) and $189/month (Plus). Pro and Enterprise Flex price on Data Workers, dedicated compute capacity, so cost doesn't depend on row counts, connector types or user seats, and CDC is included on every plan.
Connectors: a curated catalog vs. 700+
Weld builds its own connectors in-house and focuses on the sources lean analytics teams use most: ad platforms, e-commerce, CRMs, payments and common databases. Its destinations include BigQuery, Snowflake, Databricks, Redshift, Postgres, SQL Server, MySQL, Azure Synapse, S3, Apache Iceberg and a Weld-managed BigQuery warehouse. For sources outside the catalog, Premium and above let you write a custom connector in Python and host it yourself on Google Cloud Functions, AWS Lambda or Azure Functions.
Airbyte's catalog covers 700+ sources and destinations, including the long tail of SaaS tools, APIs, files and databases. When a source is missing, the Connector Builder generates one from API docs with AI assist, usually in minutes and without hosting anything yourself, and engineers can use the low-code or Python CDK. Because connectors are open source, you can also fix or extend any existing connector.
Weld puts transformation inside its own product: a SQL editor with the Ed AI assistant, version history, lineage and scheduling, plus reverse ETL to tools like HubSpot, Klaviyo and Google Ads. For a small team, one tool for the whole flow is convenient. The trade-off is that models and logic live in Weld, and dbt integration only starts on Premium.
Airbyte loads raw data into your warehouse or lakehouse and integrates natively with dbt Core, dbt Cloud, Airflow, Dagster and Prefect, so each layer of your stack stays your choice and transformation logic stays portable.
Sync frequency and CDC
On Weld, data freshness is a pricing tier. Basic syncs daily, with 6-hour syncs as an add-on. Premium reaches hourly, Business reaches 15 minutes, and 5-minute syncs need a Business add-on or Enterprise. Log-based CDC for databases isn't available on Basic or Premium at all.
Airbyte includes log-based CDC on every plan for databases such as Postgres, MySQL, SQL Server, Oracle and MongoDB, keeping destinations close to real time without moving to a higher tier.
Deployment and data residency
Weld is cloud-only SaaS. As a Danish company it suits European teams that want an EU vendor, and Enterprise customers can pick AWS, GCP or Azure, but pipelines always run in Weld's managed environment and there's no self-hosted option.
Airbyte runs four ways on one codebase: free self-hosted Core, managed cloud, hybrid with an Airbyte-managed control plane, or fully on-prem and multi-region with Enterprise Flex. Data can stay entirely inside your own boundary, which matters for data residency, regulated industries and air-gapped environments.
Developer and AI access
Weld exposes pipelines through the Weld Connect REST API and an MCP server, so AI agents in tools like Claude, ChatGPT and Cursor can trigger syncs and query the data stack. Both start on Premium.
Airbyte's core is open source, with 1,000+ contributors and 25,000+ community members. Engineers manage pipelines as code with the Airbyte API and Terraform provider, and PyAirbyte runs connectors directly from Python or notebooks, which makes it easy to feed AI applications and agents. You can inspect exactly how every connector handles your data.
Where Weld leads
Weld is a strong fit for small analytics teams, often in e-commerce and marketing, that want ingestion, SQL modeling with an AI assistant, lineage and reverse ETL in one managed tool, from an EU-based vendor with straightforward entry pricing.
When to choose Airbyte vs Weld
| Your situation | Better fit |
|---|
| You need sources outside Weld's catalog without hosting custom code yourself | Airbyte (Connector Builder) |
| You need CDC without moving to Business or Enterprise | Airbyte |
| You add connector types often and don't want per-connector fees | Airbyte |
| You have high-churn tables or growing row counts | Airbyte (capacity-based) |
| You need to self-host, run hybrid or keep data fully on-prem | Airbyte |
| You already use dbt and an orchestrator and want ingestion to plug into them | Airbyte |
| You're a small team that wants ELT, SQL modeling and reverse ETL in one managed tool | Weld |
| You want an EU-based vendor with an AI SQL assistant built in | Weld |
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