Sling Platform vs Fivetran — The Honest Comparison

Fivetran built the modern ELT category. It is well-engineered, widely deployed, and has a genuinely large connector catalog. It is also one of the loudest sources of bill shock in data engineering Slack channels.

Both Sling Platform and Fivetran are web-application-driven ELT platforms — you manage pipelines through a dashboard, set schedules, and monitor runs. This page compares them directly: where Fivetran wins, where Sling wins, and which one you should pick based on what you’re actually trying to do.

TL;DR

Where Fivetran wins

SaaS API connector breadth

Fivetran has ~500 pre-built connectors. Salesforce, NetSuite, Workday, Marketo, HubSpot, Zendesk, and hundreds more. Sling covers the major databases and 90+ REST APIs today. The api-spec format lets you add any REST source — but you write the YAML yourself rather than picking from a managed registry.

If your stack is 15+ long-tail SaaS APIs that Sling hasn’t yet built a spec for, Fivetran’s catalog wins. Full stop.

Enterprise procurement readiness

SOC 2, HIPAA, BAAs, named CSMs, SLAs printed on paper — Fivetran has all of it. If your procurement team needs a vendor security packet in two weeks, Fivetran can deliver. Sling’s security posture is different: since data never leaves your infrastructure, the surface area is smaller, but the paperwork trail is shorter.

Fully managed infrastructure

Fivetran runs everything for you. There’s no agent to deploy, no container to maintain, and no infra bill tied to sync operations. If your data team has no infrastructure engineering capacity, that simplicity is real value.

Where Sling wins

1. Pricing that doesn’t punish growth

Fivetran charges on Monthly Active Rows (MAR) — every row that moves through a connector counts against the meter. The complaints are easy to find:

“We went from $600/mo to $6,000/mo over 18 months as our data grew. The connector counts didn’t change — just the row volume.” — HN thread on “Fivetran pricing alternatives” (paraphrased from multiple public comments)

Sling Platform charges flat:

• Free tier — limited runs, no credit card required
• Standard — $99/mo flat
• Advanced — $249/mo flat

A billion-row sync costs the same as a million-row sync. No surprises at the end of the month.

2. Your data never leaves your infrastructure

Fivetran is a managed cloud service. Every row you sync flows through Fivetran’s infrastructure before landing in your warehouse. For finance, healthcare, government, or EU-GDPR-strict organizations, that is often a hard blocker — not a preference.

Sling Platform uses a self-hosted agent model. You run the agent inside your own Docker container or Kubernetes pod, in your own VPC. The control plane orchestrates jobs and stores metadata — your rows never flow through it.

# replication.yaml — runs entirely in your environment
source: MY_POSTGRES
target: MY_SNOWFLAKE

defaults:
  mode: incremental
  primary_key: id
  update_key: updated_at

streams:
  public.orders:
  public.customers:
  public.products:

Data residency, compliance auditability, lower egress costs — you’re on your own bandwidth and compute.

3. YAML-first configuration — not a dashboard black box

A Sling replication is a 12-line YAML file that lives in your git repo. You diff it, review it, roll it back, and CI/CD it. Fivetran connectors live in their dashboard. They have a Terraform provider, but it wraps their API rather than being a first-class IaC contract — and most teams don’t use it.

Sling’s YAML also gives you explicit control over behavior that Fivetran abstracts away: column type overrides, pre/post hooks, SQL transforms, custom SQL sources, per-stream primary key configuration. The editor in Sling Platform keeps all of that in one view — YAML config, run history, and connection status — without hiding it behind a settings API.

If an engineer leaves your data team and took the mental model of your pipelines with them, Sling’s YAML is the audit trail. Fivetran’s dashboard is not.

4. Schema drift handling — without the black box

Sling Platform handles schema drift. The add_new_columns target option automatically adds new source columns to the destination table when detected. The adjust_column_type option handles type evolution. Both are opt-in per stream, giving you explicit control over which tables get automated drift handling and which are locked.

The difference from Fivetran: Sling’s behavior is declared in your YAML and visible in your git history. Fivetran’s schema drift handling is automatic but opaque — when a column silently migrates, the audit trail is a Fivetran UI log rather than a git commit.

5. Open source engine, auditable code

The Sling execution engine is AGPLv3-licensed and open source on GitHub. You can read the connector code, fork it, contribute to it, or audit it. When a sync produces an unexpected result, you can trace it to a line of Go rather than opening a support ticket.

Fivetran is a closed black box. The connector logic is not visible. If you need to understand why a row landed a certain way, you’re reading logs and opening support tickets.

When to choose Fivetran

• More than half your sources are long-tail SaaS APIs (NetSuite, Workday, Salesforce CPQ, Marketo) that change schema frequently.
• Your data team does not want to manage any infrastructure — not even a Docker container.
• You’re in an enterprise procurement cycle and need vendor security paperwork in weeks.
• The pricing math works for your row volumes (i.e., you’re not at the scale where MAR billing becomes painful).

When to choose Sling Platform

• You’re primarily moving data between databases, data lakes, and file systems — not dozens of obscure SaaS APIs.
• You need data residency — your rows must not traverse a vendor network.
• You want fixed, predictable costs regardless of data volume growth.
• You’re a data engineer comfortable with a CLI and YAML and want config-as-code from day one.
• You need self-hosted or air-gapped execution — healthcare, finance, government, or secure environments.
• You want the core engine AGPLv3-licensed so you can audit and fork the connector code.

The Fivetran + dbt Labs merger

In October 2025, Fivetran and dbt Labs announced an all-stock merger. Regulatory approval is pending as of mid-2026. George Fraser (Fivetran) remains CEO; Tristan Handy (dbt) becomes President. Fivetran also acquired Census (reverse ETL) in February 2026.

If you’re an existing Fivetran customer, three things are worth watching.

The billing picture gets more complex. Fivetran’s MAR model is already the most common complaint about the product on HN and data Slack channels. dbt Cloud charges separately per seat or per model run. Under one vendor, you now have two consumption-based meters scaling independently. Whether the merger changes either pricing model is not public; what’s documented is that both exist.

The vendor concentration is real. Fivetran has acquired both the EL layer (Fivetran connectors) and the activation layer (Census). Now they own the transformation layer too (dbt Labs). If your current stack uses Fivetran for EL, dbt Core for T, and other tools for activation, expect that combination to get pushed toward Fivetran’s versions of each layer over time.

The “open” language is ambiguous. The merged entity is using “open data infrastructure” in its positioning. dbt Core is Apache 2.0; dbt Cloud is closed-source SaaS. Fivetran has no open-source offering. Sling’s core binary is AGPLv3 and the connector code is on GitHub.

None of this means you should leave Fivetran. It means a vendor review is reasonable if you’re coming up on renewal.

Switching from Fivetran to Sling

Each Fivetran connector maps to a Sling source connection plus a replication YAML. The migration approach:

1. Identify your highest-MAR connectors. Those are where the monthly cost delta is largest. Start there.
2. Set up the Sling connection for that source. Most DB and file-system connectors need only a connection string — see the docs.
3. Write a replication YAML mirroring your Fivetran sync settings (tables, mode, primary keys). Sling’s full-refresh and incremental modes cover the common cases.
4. Run a parallel sync for one week. Compare row counts between Fivetran’s output and Sling’s. Fix any edge cases.
5. Cut over — point downstream consumers at the Sling-written tables and cancel the Fivetran connector.

The process is connector-by-connector. You don’t have to move everything at once.

Try Sling Platform

Start free → — free tier available, no credit card required.

View pricing → — Standard $99/mo, Advanced $249/mo. Flat rate, no per-row metering.

Questions? Join the Sling Discord → — the founder is there every day.