Best Tool to Load Google Sheets to BigQuery (2025 / 2026 Guide)
A technical step-by-step guide to loading Google Sheets data into BigQuery, running rollups with Dataform or scheduled queries, and automatically delivering chart updates to Slack.
Best Tool to Load Google Sheets to BigQuery (2025 / 2026 Guide)
Google Sheets is where a huge amount of business data actually lives — marketing budgets, sales targets, manual survey results, finance adjustments. BigQuery is where you want to analyse it at scale with SQL.
Getting the two to talk is one of the most common data engineering tasks in any Google Cloud org. This guide covers the best approach in 2025/2026: creating a BigQuery dataset backed directly by a Google Sheet, querying it with SQL, building rollups, and then — the part most teams skip — automatically delivering those insights to your team in Slack.
Step 1: Create a BigQuery External Table from a Google Sheet
The quickest path from Sheet to SQL is a BigQuery External Table. BigQuery reads the Sheet directly from Google Drive every time you run a query — no ETL pipeline, no data copy, no stale snapshots.

How to set it up
- Open the BigQuery Console and navigate to your project.
- Select a dataset (or create a new one), then click Create Table.
- Under Create table from, choose Google Drive.
- Paste your Google Sheets URL into the Drive URI field.
- Set the File format to
Google Sheets. - If your Sheet has a header row, check Auto detect under Schema, or define columns manually.
- Click Create Table.
That's it. You now have a table you can SELECT from using standard SQL.
SELECT
campaign,
SUM(spend_usd) AS total_spend,
SUM(conversions) AS total_conversions
FROM `your-project.your_dataset.marketing_spend`
WHERE month = '2026-01'
GROUP BY campaign
ORDER BY total_spend DESC;
When to use an External Table
| External Table | Native BQ Table | |
|---|---|---|
| Data freshness | Always live | Depends on copy schedule |
| Query speed | Slower (reads from Drive) | Fast |
| Cost | Query costs on every run | Storage + cheaper queries |
| Best for | Reference data, small tables, manual inputs | Analytical workloads, joins at scale |
For lookup tables, budget trackers, and manually maintained data — External Tables are excellent. For anything you're joining against millions of rows or running on a tight latency budget, you'll want to copy the data into a native table (see Step 3).
Step 2: Query Your Sheet Data in BigQuery
Once your External Table is set up, the full power of BigQuery SQL is available against your Sheet data. You can join it with other warehouse tables, filter by date, aggregate, window function — anything.
A common pattern is joining your Sheet data against event tables to enrich raw data with human-maintained metadata:
-- Join warehouse events with a manually-maintained Sheet mapping
SELECT
e.user_id,
e.event_name,
e.occurred_at,
m.account_tier,
m.region
FROM `your-project.events.page_views` e
JOIN `your-project.sheets.account_metadata` m
ON e.account_id = m.account_id
WHERE e.occurred_at >= TIMESTAMP_SUB(CURRENT_TIMESTAMP(), INTERVAL 7 DAY);
This is the core value: your Sheet becomes a first-class citizen in your SQL warehouse.
Step 3: Build Rollups — Staying Native GCP vs External Tools
Raw data in BigQuery is rarely what stakeholders need. You'll want to compute rollups — weekly totals, month-over-month comparisons, rolling averages. Here are the main options in 2026:
Option A: BigQuery Scheduled Queries (simplest, fully native)
BigQuery has a built-in Scheduled Queries feature that runs any SQL on a cron schedule and writes results to a destination table. Zero infrastructure required.
- Go to BigQuery Console → Scheduled Queries → Create Scheduled Query
- Write your rollup SQL
- Set the schedule (daily, hourly, weekly)
- Point the output at a destination dataset/table
Best for teams who want to stay entirely within GCP with minimal setup.
Option B: Dataform (recommended for native GCP)
Dataform is Google's native SQL transformation framework, now fully integrated into BigQuery Studio. It gives you:
- Version-controlled SQL in a Git-backed workspace
- Dependency graphs so rollups run in the right order
- Documentation and column-level lineage built in
- Scheduled runs via Dataform workflows
// dataform.json example — weekly_campaign_rollup.sqlx
config {
type: "table",
schedule: { cron: "0 6 * * 1" } // every Monday at 6am
}
SELECT
DATE_TRUNC(date, WEEK) AS week_start,
campaign,
SUM(spend_usd) AS weekly_spend,
SUM(conversions) AS weekly_conversions,
SAFE_DIVIDE(SUM(spend_usd), SUM(conversions)) AS cpa
FROM ${ref("marketing_spend")}
GROUP BY 1, 2
Dataform is the best choice if your team is already on GCP and you want proper software engineering practices around your SQL transformations.
Option C: dbt (open source, cloud-agnostic)
dbt (data build tool) is the most popular open-source transformation framework. It works with BigQuery and gives you the same version control and testing benefits as Dataform, but is not tied to GCP.
Good choice if your team already uses dbt, or if you want to stay cloud-agnostic.
Option D: Managed ETL / Reverse ETL tools
For teams that want a no-code or low-code approach:
- Fivetran — automated connectors that sync Google Sheets into BQ on a schedule
- Airbyte — open-source alternative to Fivetran with a self-hosted option
- Stitch — lightweight ETL, good for smaller teams
- n8n — workflow automation that can handle Sheet → BQ pipelines with custom logic
These are worth considering when the transformation logic lives in the pipeline rather than in SQL.
Now: Get Regular Chart Updates Into Slack
You've got your Google Sheet loading into BigQuery. You've got rollups running on a schedule. Your data is clean and current.
The problem most teams hit next: nobody sees it.
Stakeholders don't log into BigQuery. They're in Slack. They have three dashboards bookmarked and check none of them. The insight you worked to build sits unread until someone manually pastes a screenshot into a channel — if at all.
Automate the last mile in 2 minutes with Chartcastr
Chartcastr connects directly to your Google Sheet and automatically delivers chart updates to Slack on your schedule — no code, no dashboards to maintain.

The workflow is:
- Connect your Google Sheet — paste the URL, select the data range or an existing chart.
- Pick a Slack channel — the one your team actually reads.
- Set a schedule — daily at 9am, weekly on Monday, whenever makes sense.
- Chartcastr delivers — a clean, high-resolution chart image with an AI-written summary explaining what moved and why.
Your BigQuery rollup writes the results back to a Sheet (or you use the Sheet as the source directly), and Chartcastr handles the rest.
No more screenshots. No more "can someone pull the numbers for standup?" No more dashboards that get checked once and forgotten.
Set up your first Sheet → Slack pulse for free →
Summary
| Step | What to use |
|---|---|
| Load Sheet into BigQuery | External Table (live) or Scheduled copy (performant) |
| Transform & roll up | Dataform (native GCP), dbt (open source), or Scheduled Queries |
| Deliver insights to team | Chartcastr → Slack |
The pipeline from Google Sheets to BigQuery to Slack is one of the most common in modern data teams — and in 2026, every step of it can be automated without writing application code.