---
title: Output formats
description: Choose GeoJSON, CSV, GML, KML, or HTML with the f= parameter, and know which JSON envelope you are getting.
---

Select the response format with `f=`:

| Format                             | `f=` value                             |
| ---------------------------------- | -------------------------------------- |
| GeoJSON (standard — recommended)   | `application/geo+json`                 |
| GeoJSON (legacy envelope)          | `application/json`                     |
| CSV                                | `text/csv`                             |
| GML 3.2                            | `application/gml+xml;version=3.2`      |
| KML                                | `application/vnd.google-earth.kml+xml` |
| HTML (browser)                     | `text/html`                            |

Without `f=`, the format is negotiated from the `Accept` header: browsers get HTML (nice
for exploring), while `curl` and HTTP libraries get JSON. Pin `f=` anyway so the response
never depends on what your client happens to send.

## The two JSON formats

`application/geo+json` and `application/json` return the **same features** wrapped in
different envelopes:

- **`application/geo+json`** — standard [RFC 7946](https://datatracker.ietf.org/doc/html/rfc7946)
  GeoJSON and the canonical OGC API - Features representation: `numberReturned`,
  `timeStamp`, and a full `links` block (`self`, `alternate`, `collection`, `next`).
  **Use this one.**
- **`application/json`** — a legacy GeoJSON envelope: adds a non-standard
  `crs` member and `totalFeatures: "unknown"`, and carries only a bare `next` link.

Both page the same way (each response has a `next` link when more results exist). On the
service metadata pages (landing page, conformance, `/collections`), plain
`application/json` **is** the JSON format — `geo+json` is for feature responses.

## Examples

CSV — drop straight into a spreadsheet or `pandas`:

```bash
curl -sG -H "Authorization: Bearer $TOKEN" \
  "https://api.deepfire.co/ogc/features/v1/collections/deepfire:hotspots/items" \
  --data-urlencode "bbox=-125,32,-114,42" \
  --data-urlencode "filter-lang=cql2-text" \
  --data-urlencode "filter=active = true" \
  --data-urlencode "f=text/csv" -o hotspots.csv
```

KML — open in Google Earth:

```bash
curl -sG -H "Authorization: Bearer $TOKEN" \
  "https://api.deepfire.co/ogc/features/v1/collections/deepfire:satellite-perimeters/items" \
  --data-urlencode "filter-lang=cql2-text" \
  --data-urlencode "filter=active = true" \
  --data-urlencode "limit=1000" \
  --data-urlencode "f=application/vnd.google-earth.kml+xml" -o perimeters.kml
```