# Email Tracking Pixel Detector
Paste raw email source or HTML to find 1x1 tracking pixels, hidden remote images, known tracker domains, CSS beacons, prefetch assets, and optional click trackers.
## Run it
- **CLI:** `gizza tool email-tracker-pixel-detector 'Paste raw .eml source or HTML email markup, e.g. 
'`
- **Web:** https://gizza.ai/tools/email-tracker-pixel-detector/
- **Agents:** machine-readable descriptor (parameters JSON Schema) at https://gizza.ai/tools/email-tracker-pixel-detector/tool.json
## Inputs
- `text` — Email source or HTML _(field)_
- `format` — Input type _(field)_
- `report` — Report _(field)_
- `include_links` — Also inspect links for click tracking _(field)_
- `vendors` — Extra tracker domains _(field)_
## Output
- Tracking report (text)
## Query parameters
Open the tool pre-filled and auto-run via URL:
- `text` — Email source or HTML
- `format` — Input type
- `report` — Report
- `include_links` — Also inspect links for click tracking
- `vendors` — Extra tracker domains
Example: `https://gizza.ai/tools/email-tracker-pixel-detector/?text=Paste%20raw%20.eml%20source%20or%20HTML%20email%20markup%2C%20e.g.%20%3Cimg%20src%3D%22https%3A%2F%2Ftrack.example%2Fopen.gif%3Fu%3Dabc%22%20width%3D%221%22%20height%3D%221%22%3E&format=auto&report=summary&include_links=true&vendors=track.example.com%2C%20email.your-esp.test`
---
## About this tool
Email Tracking Pixel Detector inspects raw email source or HTML markup for the remote assets that can report when a message is opened. It looks for tiny `1×1` or `0×0` images, CSS-hidden images, known email-service and sales-tool tracking hosts, open/pixel/beacon URL paths, unique recipient IDs in query strings, CSS `background-image` beacons, and prefetch/preload links.
Everything runs locally in your browser. The detector never fetches the image, follows a redirect, resolves DNS, opens a mailbox, or uploads your email. A `TRACKED` result means the pasted markup declares at least one high-confidence open tracker. `LIKELY_TRACKED` means a remote asset has structural tracking signals but no known vendor match. `REMOTE_CONTENT` means the email would contact a remote host even though no tracker-specific signal was found.
### Worked example
Paste this HTML:
```html
```
The summary reports `TRACKED`, lists `track.hubspot.com` as a host contacted on open, and explains the signals: known tracker domain, tiny pixel, hidden CSS, tracking path, and unique ID query.
Set **Report** to **Hosts only** when you want a paste-ready list for a mail rule, firewall, or content blocker. Add private ESP or CDN hosts in **Extra tracker domains** when your organization rewrites tracking links through a custom domain.
### Limits and edge cases
- The vendor table is a curated snapshot. Unknown hosts are still flagged when their markup looks like a tracker, and you can add custom hosts with the `vendors` field.
- Raw `.eml` input is scanned as pasted source. Encoded MIME parts that do not expose their HTML after export may need to be decoded by your mail client first.
- The tool does not perform network I/O, so it cannot inspect HTTP headers, ETags, cookies, redirects, or live reputation feeds.
- A `CLEAN` result only means no remote image/prefetch/link tracker was declared in the pasted markup. It cannot see content that your mail client would fetch or rewrite later.
## FAQ
What counts as a tracking pixel?
A high-confidence tracking pixel is usually a remote image that is tiny, hidden, hosted on a known email-tracking domain, or loaded from a URL containing open, pixel, beacon, tracking, or recipient-ID parameters. The tool reports every signal it used so you can verify the finding instead of trusting a black-box badge.
Does this block the tracker?
No. This is a detector, not a mail-client extension. It does not load or rewrite the email. Use the **Hosts only** report to copy remote hosts into a blocker or mail rule, or disable remote images in your mail client before opening suspicious messages.
Why are normal remote images reported?
Any remote image can reveal your IP address, rough location, mail client, and open time to the server that hosts it. If the image has no tracker-specific signal, the verdict is `REMOTE_CONTENT` instead of `TRACKED`, but it is still listed so you can decide whether loading it is acceptable.
Should I turn on link inspection?
Turn on **Also inspect links** when you want click-tracking hosts too. It is off by default because open tracking and click tracking answer different questions: an image can fire when you merely open a message, while a link only reports if you click it.
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