API Connectivity Test answers one question: do the keys and addresses I entered in the settings actually work? It sends one real, minimal request per service — the OpenAI-compatible entry first tries GET /models and falls back to a one-token chat call if that is unavailable; remove.bg queries the /v1.0/account balance; OCR.space posts a canvas-drawn test image reading “HELLO 123”; DeepLX translates “hi”; DeepL Free queries /v2/usage — and reports the outcome with a green or red icon, a millisecond latency and a note.

The lower half covers the free public endpoints that other tools on this site rely on (MyMemory, is.gd, ipwho.is, Open-Meteo and Frankfurter). They need no configuration and tell you whether an outage is upstream or on your own network.

1. 01Configure keys— fill in the services you want to test on the settings page first; entries without a key show a grey “No API key configured” with a Configure link and are skipped when testing.
2. 02Test everything— click Test all; every enabled entry runs concurrently, and each row shows a status icon, the latency in milliseconds and a note or failure reason.
3. 03Retest one entry— after changing a setting, click the refresh icon at the right of that row to retest it on its own.
4. 04Read the result— green notes look like “Connected, 37 models available” or “Key valid, 50 free credits per month”; red errors have the key redacted to *** or sk-***.

It makes real calls

— the OpenAI test costs about one token, OCR.space spends one recognition credit, and is.gd really creates a short link pointing at example.com.

Timeouts

— 30 seconds per entry, recorded as a failure; the latency includes the TLS handshake and is higher on the first run.

Connectivity and authentication only

— it does not judge model quality or translation accuracy, and results are not saved: refreshing clears them.

What it does not do

— it does not measure bandwidth (use Speed Test), does not replace the provider's usage dashboard and does not fix any configuration.

Each test sends the matching key and a minimal sample request straight to that provider (api.openai.com or your configured address, api.remove.bg, api.ocr.space, your DeepLX address, api-free.deepl.com) and to the five free public endpoints; this site neither handles nor records the results. The ipwho.is test exposes your public IP address to that service.