527 Explorer

Tool Description : A ProPublica database that lets you track political “527” organisations in the US i.e. groups that raise and spend money to influence elections.

527 Explorer

Quick Overview

URL

https://projects.propublica.org/527-explorer/

What it does

It maps the financial activity of US political 527 organisations, showing donations coming in, spending going out, and organisational networks behind political influence operations.

How to use it

Search for an organisation, open its profile and review funding sources, expenditure breakdowns, and linked entities, then follow money flows across related groups.

Cost

Free.

Account required

No.

A mix of Google authentication cookies, security and consent cookies, location personalisation data, and third-party advertising tracking identifiers.

Ownership

Created and maintained by ProPublica (US non-profit investigative journalism organisation).

Use in Reporting

Useful to track political funding networks, identify donors behind advocacy/influence campaigns, analyse spending patterns around elections, and support transparency reporting on campaign finance.

What does 527 Explorer do?

527 Explorer provides a searchable map of US 527 political organisations, which are tax-exempt groups that influence elections but are not officially tied to candidates or parties.

The tool shows who funds such groups, how much money flows through them, and where that money is going.

The lowdown: It’s essentially a financial transparency lens on political influence groups.

How to Use:

1. Search for a political organisation, committee, or known group on the 527 Explorer home page.

2. Open the organisation profile page and analyse donor lists, spending categories, financial totals over time, and connected organisations.

Cost

Free
Partially Free
Paid

Data Processing

Account Required:

Cookies:

Cookies are mainly used by Google services for user authentication (login/session management), account security and fraud prevention, tracking signed-in activity across Google services, and location/personalisation signals (search and ads relevance).

Use in Reporting

527 Explorer is used to:

Investigate political influence networks.
Identify funding sources behind advocacy campaigns.
Track election-related spending patterns.
Support transparency in political finance reporting.
Corroborate claims about donor influence.

The tool is widely used in investigative reporting as a ProPublica campaign finance data tool, but is usually cited indirectly as part of ProPublica’s political finance datasets. See recent example here from DW News entitled “From kings and aristocrats to Jeff Bezos or Elon Musk: How the rich avoid taxes.”

Capabilities

Limitations

Searchable database of US 527 organisations.

Only covers registered 527 organisations (not all political money flows).

Donor and expenditure breakdowns.

Dependent on publicly filed financial disclosures (delayed reporting).

Organisation-level financial profiling.

Limited content on intent/informal coordination.

Historical funding patterns.

US-focused only.

Network tracing between political groups.

Cannot capture off-books or unreported financial activity.

Summary

527 Explorer is best used in the analysis and verification stages of OSINT investigations focused on political finance and influence networks, where it helps map and validate how money flows between organisations.

Ownership

Created and maintained by ProPublica, an American non-profit investigative journalism organisation based in New York.

Ethical Considerations

Data relates to political activity so handle carefully to avoid partisan framing.
Be mindful of the risk of misinterpreting lawful donations as wrongdoing.
Use for transparency, not targeting individuals.
Consider the context of legal political advocacy.
Avoid drawing conclusions without corroborating evidence.