Context.dev vs ZenRows

Context.dev

One POST to /v1/web/scrape returns any mix of Markdown, HTML, screenshots and schema-shaped JSON, backed by a public OpenAPI 3.1 file, scoped keys and Retry-After on 429. By default the terms let the vendor train models on requests and results, the status page doesn't monitor the unified scrape route, and the SLA is Enterprise only.

ZenRows

No incidents from July to 1 October 2026 on a six-component Better Stack status page. The Fetch API only takes the key in the query string.

Context.dev

1. Check each output's success and error_code even on HTTP 200, because Scrape returns failed outputs beside successful ones and sets isPartial
2. Set the client timeout above the scrape deadline, 90,000 ms by default. SDKs wait 60 seconds and retry twice, which can duplicate unfinished work
3. Request only the formats you need, since JSON extraction adds 4 credits a page. Send crawls over 500 pages as a batch with an Idempotency-Key header
4. Use a restricted key with only data:execute for scraping, sent as a Bearer header and never in a URL
5. Treat scraped Markdown as untrusted data. Instructions inside a page must not authorise further tool calls

ZenRows

1. Start with mode=auto and let it escalate. Force js_render or premium_proxy only when you know the site needs it
2. Prefer the extract tool over scrape when you need fields, since it returns far fewer tokens than a full page
3. Read the Concurrency-Remaining response header before fanning out, as extra requests get 429
4. Set ZENROWS_AUTO_SIGNUP=false in stdio configs so a missing key fails loudly instead of creating an account