Your Data Stays Private
Unlike other chart tools, CleanChart never stores your files. Your data is processed in memory just long enough to build your chart, then discarded.
Your Files Are Never Stored
Your file is read and previewed directly in your browser. For cleaning and chart rendering, data is sent over HTTPS, processed in memory, and discarded immediately — it is never written to disk or a database. One exception, only if you ask for it: when you explicitly request a chart download link (available via our MCP integration), the finished chart image — never your underlying data — is kept for 24 hours behind an unguessable link, then deleted automatically.
Your Values Stay Yours
We never store the contents of your files, sell your data, or train AI models on it. To improve the app we keep only anonymous structure metadata — column names and data types, never cell values.
Transient Server Processing
Our servers handle authentication, payments, cleaning analysis, and chart rendering. Your data exists there only for the seconds it takes to process, in memory, and is gone as soon as your chart is returned.
Nothing Left Behind
Your chart downloads straight to your device — we keep no server-side copy of your file or your finished chart. Close the tab and it's gone.
How Your Data Is Handled
You upload a file
When you select a CSV or Excel file, it's read and previewed directly in your browser using JavaScript. Nothing is uploaded at this point.
We analyze and clean it — in memory
To detect quality issues and apply fixes, your data is sent to our servers over HTTPS, processed in memory, and returned. It is never written to disk, logged, or stored.
Your chart is rendered and your data discarded
Our rendering service (Python with matplotlib and seaborn) turns your data into a PNG or SVG image and sends it back to your browser. The data is discarded the moment rendering finishes. The chart image itself is stored only if you explicitly request a download link (MCP), and only for 24 hours.
Only structure metadata is kept
To improve our recommendations we keep anonymous structure metadata — column names, data types, and aggregate counts. Never cell values, and never the chart image itself.
What Information We Collect
Account Information
When you sign up, we collect your email address and name (via Google OAuth). This is used solely for authentication and account management.
Generated Charts
We do not store your generated charts. The chart image is returned to your browser for download and no server-side copy is kept.
Usage Analytics (Umami — cookie-free)
We use Umami Analytics (privacy-friendly, GDPR-compliant) to track basic usage metrics like page views and feature usage. Umami does not use cookies, does not track users across websites, and does not collect personal information. All analytics data is anonymized. Learn more: https://umami.is/docs/privacy
Session Analytics (Microsoft Clarity — requires consent)
With your consent, we use Microsoft Clarity to record anonymized session replays and heatmaps. This helps us understand how users interact with the app and identify usability issues. Clarity uses cookies and may collect IP address, device type, and interaction data. You can accept or decline this tracking via the cookie banner shown on your first visit. Declining does not affect core functionality. Learn more: Microsoft Privacy Statement
Repeat-Upload Cookie (first-party)
When you upload a file, we set a single first-party cookie (cc_vid) containing a randomly generated ID. It holds no personal information, is not readable by page scripts, is never sent to any third party, and cannot follow you to other websites. Its only purpose is to tell us whether several uploads came from the same browser, so we can measure how often our chart recommendations work on a second or third try. The cookie expires after one year, and clearing your browser cookies removes it — the app works exactly the same without it.
File Structure Metadata
To improve our cleaning and chart recommendations, we collect the column headers and inferred data types (e.g. “date”, “numeric”, “text”) of uploaded files — both before and after cleaning. We also record aggregate statistics such as row count, column count, and which cleaning operations were applied.We never store your dataset. In rare diagnostic cases — when a column’s format defeats our detectors or a chart fails on a specific column — we retain a handful of truncated sample values from that column (never whole rows or files) so we can add support for that format. These diagnostic samples are automatically deleted after 180 days. Because the remaining structural metadata contains no cell values, we retain it for as long as it is useful for improving the app, and it is used solely for that purpose.
Payment Information
Payments are processed securely through Polar. We never see or store your credit card information.
AI-Assisted Processing (Anthropic Claude)
We use Anthropic’s Claude AI in two narrow, behind-the-scenes ways: if you type a short free-text answer describing what kind of data you uploaded (e.g. “project schedule”), that answer may be sent to the Claude API to sort it into a category; and we use Claude internally to summarize aggregate, anonymized usage statistics for our own reports. Unless you buy a project report (below), your files, cell values, and column headers are never sent to any AI model, we never use your data to train AI models, and Anthropic does not train its models on data submitted via its API. Learn more: Anthropic Privacy Policy
Paid Project Reports
When you buy a project report, or generate one with a 24-hour pass or subscription, we analyze your Gantt data on our servers and send the results to the Claude API to write the report’s summary: task and phase names, dates and the computed figures and findings — never your raw rows. Person names (for example task owners) are replaced with placeholders such as “Owner A” before anything is sent; the real names appear only in your PDF. Nothing is sent to Claude before your purchase or pass is confirmed. For one-time reports, the project data needed to produce and re-download your report is kept for 24 hours after your last download, then deleted automatically. Anthropic does not train its models on this data.
Third-Party Service Providers
We rely on a small number of service providers to run CleanChart. Each one receives only the minimum data needed to perform its role on our behalf, and none of them may use your data for their own purposes. We never sell your data.
- ✓ Vercel — hosts the website and processes requests (including your data, in memory, during cleaning)
- ✓ Amazon Web Services (AWS) — renders your chart in a serverless function; your data is processed in memory and discarded
- ✓ MongoDB — stores account information and the anonymous structure metadata described above
- ✓ Polar.sh — payment processing, subscriptions, and billing portal
- ✓ Google — optional sign-in via Google OAuth (email and name only)
- ✓ Resend — sends transactional emails such as sign-in links
- ✓ Anthropic — AI categorization and internal reporting, as described above, and writing paid project reports (only after purchase; person names pseudonymized)
- ✓ Umami — cookie-free, anonymized usage analytics
- ✓ Microsoft Clarity — optional session analytics, only with your cookie consent
- ✓ Upstash — rate limiting infrastructure to protect the service from abuse, and short-lived storage (at most 24 hours) of the data behind a single-chart or project-report purchase
What We DON'T Collect
- Your CSV/Excel files - Never stored; processed in memory only during cleaning and rendering
- The content of your data - We never store your rows or files. We do collect column names and data types, plus — in rare diagnostic cases — a few truncated sample values from a problematic column, deleted after 180 days (see “File Structure Metadata” above).
- Browsing behavior - We use Umami (GDPR-compliant, cookie-free) and optionally Microsoft Clarity (session replays, requires cookie consent) to improve the app. Our own first-party cookie only groups your uploads on this site — it does not track you anywhere else
- Personal information - beyond email for authentication
Your Privacy Rights (GDPR)
We respect your privacy rights. You can:
- ✓ Request a copy of your data (charts and account info)
- ✓ Delete your account and all associated data
- ✓ Opt out of analytics (contact us)
- ✓ Use the app without creating an account (limited features)
To exercise these rights, please contact us at [email protected]
Data Retention
We keep your data for as long as you have an active account. If you delete your account, we will permanently delete all your charts and account information within 30 days.
Anonymous product telemetry (the file-structure metadata described above) is keyed by a random session identifier and is never linked to your account, so it is retained on its own schedule independent of account deletion: structural metadata for as long as it is useful for improving the app, and diagnostic sample values for 180 days. The repeat-upload cookie described above lets us group several of these anonymous sessions as coming from one browser; it still carries no account link and no personal data.
Project data for a one-time report purchase is kept for at most 24 hours after your last download of that report, then deleted automatically.
Note: Payment records may be retained longer for tax and legal compliance purposes.
Security
We use industry-standard security measures:
- ✓ HTTPS encryption for all connections
- ✓ Secure authentication via NextAuth + Google OAuth
- ✓ Regular security audits and updates
- ✓ Your data is shared only with the service providers listed above, acting on our behalf — never sold, and never shared for advertising
Policy Updates
We may update this privacy policy from time to time. We'll notify you of significant changes by email or through a notice in the app.
Last updated: October 8, 2026