---
title: "Stream a big list, up to 100,000"
method: POST
path: "/api/free-proxy/check"
tags: ["Proxy checker API"]
---

# Stream a big list, up to 100,000

`POST /api/free-proxy/check`

## Request

- Base URL: `https://hproxy.com`
- URL: `https://hproxy.com/api/free-proxy/check`
- Auth: none required

The endpoint behind our [online proxy checker](/proxy-checker-online) page. POST the list and read the answer as **NDJSON**: one JSON line per proxy, in the shape above, written the moment that proxy settles, so you can show results while the rest are still running. The same limits apply, counted per proxy.

Two kinds of event lines ride along; skip any line that has an `_event` key you do not know. `{"_event":"progress","done":N,"total":M}` arrives every 15 seconds, and `{"_event":"end","total":M,"done":M,"duration_ms":N}` closes a finished batch. **A stream that stops without the end line was cut** (a network drop, or a restart on our side): the lines you have no row for were not checked, so send just those again.

If your list is big enough that the run takes minutes, hand it over as a [job](#check-jobs-create) instead: nothing stays connected, and an interrupted job resumes by itself.

## Request body

- object
  - `proxies` unknown[], required: Up to 100,000 proxy lines.
    - unknown
  - `timeout_ms` integer: Per-probe budget, 1,000 to 60,000. Default 8,000.
  - `retries` integer: Extra attempts for a proxy that does not answer, 0 to 3. Default 0.
  - `protocols` unknown[]: Any of http, https, socks4, socks5. Default all four.
    - unknown
  - `measure_speed` boolean: Also measure download speed through each working proxy (speed_mbps).
  - `measure_udp` boolean: Also test whether each working SOCKS5 proxy relays UDP (supports_udp).

## Response `200`

Success

- object

## Other responses

- `400`: Invalid input. The body names the field and the accepted set.
- `401`: Missing or invalid API key.
- `429`: Rate limited. Retry after the delay in the response.

---

[API](https://skmtc.dev/hproxy/apis/hproxy-api.md) · [All operations](https://skmtc.dev/hproxy/apis/hproxy-api/llms.txt) · [OpenAPI document](https://skmtc.dev/hproxy/apis/hproxy-api/revisions/9f6898fe76e2?raw)