Developer Tools vs Resend

devtools.tr is a free toolbox of 173 web and developer tools for webmasters, developers and system administrators. Every check runs live against real servers: DNS lookup, SSL/TLS and security headers, website analyzer with PDF reports, SEO and Core Web Vitals, TTFB, CDN and compression tests, IP geolocation, WHOIS, ASN and blacklist checks. Developer utilities include a JSON formatter and validator, regex tester, Base64, UUID, SQL/HTML/CSS/JS formatters and minifiers. Results come as clear reports with scores and ready-to-paste fixes for Apache, nginx and Cloudflare. No sign-up, no limits, fully in English and Turkish, and works on mobile.

Resend is an email API for developers, founded by Zeno Rocha and backed by Y Combinator. It focuses on developer experience: a clean REST API, official SDKs for Node.js, Python, Go, Ruby, PHP, Java and other languages, guided domain setup with DKIM and SPF records, and React Email, the open-source library from the same team that lets you build email templates as React components instead of fragile HTML tables.

The platform covers transactional sending with batch sends, scheduled emails, idempotency keys and attachments, webhooks for delivery, bounce, open and click events, logs and analytics, suppression lists, and dedicated IPs on higher tiers. Broadcasts and audiences add basic marketing email with unsubscribe handling, so product updates and newsletters can go out from the same account. A free plan includes 3,000 emails per month with a 100-per-day cap and three domains, and paid Pro and Scale plans raise volume, domains and webhook endpoints, with enterprise contracts above that.

Resend fits developers and startups, especially in Next.js, Vercel and Supabase stacks, who want transactional email that takes minutes to integrate. Data retention is 30 days on self-serve plans, deliverability tooling is lighter than that of older providers, and the marketing features are basic compared with dedicated platforms. Postmark is the veteran known for transactional deliverability, SendGrid and Mailgun are larger and more complex, Amazon SES is cheapest at very high volume, and Loops or Customer.io handle lifecycle marketing.