---
title: "Compare 2..5 vehicles, bounded by max_compare (N units)"
method: POST
path: "/v1/compare_vehicles"
---

# Compare 2..5 vehicles, bounded by max_compare (N units)

`POST /v1/compare_vehicles`

## Request

- Base URL: `https://api.theusedcarindex.com`
- URL: `https://api.theusedcarindex.com/v1/compare_vehicles`
- Auth: one of:
  - HTTP bearer
  - API key in header `X-API-Key`

## Request body

- object
  - `vehicles` VehicleInput[], required
    - `make` string, required
    - `model` string, required
    - `year` integer, required

## Response `200`

Success

- Comparison
  - `vehicles` object[], required
    - `key` string, required
    - `vehicle` object, required
    - `not_found` boolean, required
    - `suggestions` object[]
    - `complaints` object, nullable, required
    - `recalls` object, nullable, required
    - `investigations` object, nullable, required
    - `manufacturer_communications` object, nullable, required
    - `rate` Rate, required
      - `complaints_per_100k_sold` number, nullable, required
      - `units_sold` number, nullable, required
      - `sales_year` number, nullable, required
      - `basis` string, nullable, required
      - `source` string, nullable, required
      - `source_url` string, nullable, required
      - `null_reason` string, nullable, required
    - `top_systems` object[], required
      - `system` string, required
      - `count` integer, required
  - `comparison` object, required
    - `fewest_complaints_per_100k` object, required
      - `ordered` string[], required
      - `unrated` string[], required
    - `most_recalls` string[], required
    - `most_complaints` string[], required

## Other responses

- `400`: RFC 9457 problem with stable code; 429 includes Retry-After.
- `401`: RFC 9457 problem with stable code; 429 includes Retry-After.
- `403`: RFC 9457 problem with stable code; 429 includes Retry-After.
- `404`: RFC 9457 problem with stable code; 429 includes Retry-After.
- `405`: RFC 9457 problem with stable code; 429 includes Retry-After.
- `413`: RFC 9457 problem with stable code; 429 includes Retry-After.
- `415`: RFC 9457 problem with stable code; 429 includes Retry-After.
- `429`: RFC 9457 problem with stable code; 429 includes Retry-After.
- `500`: RFC 9457 problem with stable code; 429 includes Retry-After.
- `503`: RFC 9457 problem with stable code; 429 includes Retry-After.

---

[API](https://skmtc.dev/theusedcarindex/apis/the-used-car-index.md) · [All operations](https://skmtc.dev/theusedcarindex/apis/the-used-car-index/llms.txt) · [OpenAPI document](https://skmtc.dev/theusedcarindex/apis/the-used-car-index/revisions/80dd1305d05c?raw)