Sooner or later, every digital product needs to send an email that isn't marketing: a password reset, an order confirmation, a shipping notice. That email comes from your backend, not a campaign tool — and the piece of infrastructure that makes it possible is what's called transactional email. It's invisible until the day it breaks, and that's exactly when a user can't get into their account or a customer never gets their payment confirmation.
At Cambalache Studio we wire transactional email into almost every product we build, and today Resend is our default with real clients. This comparison with SendGrid isn't an abstract feature ranking — it's the same logic we used in Stripe vs Mercado Pago: it depends on what you actually need and what stage you're at.
What Both Solve (and What They Don't)
At the core, Resend and SendGrid solve the same problem: sending programmatic emails triggered by events in your product — welcome messages, password resets, invoices, status notifications — through an API or SDK you call from your backend. Neither is a mass email-marketing tool (newsletters, segmented campaigns to your whole list), even though both bolt on some version of that as an add-on product. If you're looking to send a weekly newsletter to 50,000 subscribers, this isn't the comparison you need. If you're looking to have your product tell a user their account was created, it is.
Resend: The New Option, Built to Integrate Fast
Resend is the younger of the two, built by and for teams already working with modern stacks. That shows up in three concrete ways:
- Simple developer experience. The API has few concepts, and the docs are short because they don't need to be longer. Sending your first test email takes minutes, not an afternoon of reading documentation.
- Native integration with React Email and Next.js. If your stack is already React/Next — which is the case for most products we build — you write the email template as a React component and preview it like any other piece of your UI. That removes real friction: table-based HTML emails from the 2000s stop being their own separate world.
- Focus on the essentials. A smaller product surface means less configuration before you send your first real email.
The trade-off: Resend has fewer years in the field and a smaller feature catalog. If you need something very specific around compliance or large-scale sub-account management, it's still a younger platform.
SendGrid: The Established Player, With More Surface Area
SendGrid has been around since 2009 and is part of Twilio — by a wide margin, it's the more mature option on the market. That also shows up in three ways:
- More compliance and enterprise features. Granular sub-user management, access controls, audit trails, certifications that larger companies require in their procurement processes.
- More proven IP reputation at high volume. Years of dedicated infrastructure mean SendGrid has more mature mechanisms for handling dedicated IPs and warm-up at high sending volumes.
- Integration with the rest of the Twilio ecosystem. If your company already uses Twilio for SMS or WhatsApp, adding SendGrid keeps everything under one provider and one bill.
The trade-off: the API and dashboard have more concepts, more screens, and more decisions to make before you send your first email. It's not worse, it's more — and "more" costs integration time when what you actually need is speed.
The Comparison at a Glance
| Resend | SendGrid | |
|---|---|---|
| Age | New (2023) | Established (since 2009) |
| Developer experience | Very simple, minimalist by design | Full-featured, steeper learning curve |
| Entry-level pricing | Generous free tier, accessible paid plan | More limited free tier, scales with volume |
| Deliverability / reputation | Solid for small-to-medium volume | Very proven at high volume, years of infrastructure |
| Support | Self-serve, community, docs-first | Enterprise support, SLAs, compliance |
| Integration curve | Minutes with modern stacks (React/Next) | More configuration, more API surface |
No row in this table "always wins" — each one carries different weight depending on your situation.
When Each One Makes Sense
Resend makes sense if: you're launching a new product, your team is small, you already work with React or Next.js, and the priority is having email working this week without dedicating days to integration. It's what we default to on the MVPs we build — the speed of integrating fits the same logic we covered in how we use AI to launch products fast: less operational friction, more time spent on the product itself.
SendGrid makes sense if: you're a larger company with specific compliance requirements (regulated industries, for instance), you already have a relationship with Twilio, or your sending volume is high enough that you need the reputation-management and dedicated-IP tooling that comes from years of operating at that scale.
The Practical Fact Nobody Mentions in the Sales Demo
Here's the most important part of this piece, and it's something neither Resend nor SendGrid will highlight on their landing page: deliverability depends far more on your domain configuration than on which provider you pick.
The three DNS records that determine whether your email lands in the inbox or in spam are SPF, DKIM, and DMARC. In plain terms:
- SPF tells receiving mail servers which services are allowed to send email on behalf of your domain.
- DKIM cryptographically signs each email to prove it wasn't tampered with in transit.
- DMARC tells servers what to do when an email fails those checks, and sends you reports on who's sending email "as you."
If you don't configure these three records correctly, neither tool will save you from landing in spam. And conversely: with SPF, DKIM, and DMARC set up properly, both Resend and SendGrid deliver well. Which provider you pick matters for your development speed and your operating costs — it isn't the variable that decides most of whether your email actually arrives.
Conclusion
There's no universal answer between Resend and SendGrid, just like there isn't one between Stripe and Mercado Pago: it depends on where you're standing. If you're getting a product off the ground, your team is small, and you want something working in minutes, Resend is the lower-friction option — that's why it's our default today. If you're a larger company with specific compliance requirements or already living inside the Twilio ecosystem, SendGrid carries years of enterprise infrastructure that Resend doesn't need to replicate yet. Either way, don't forget the part that actually decides whether your email arrives: setting up SPF, DKIM, and DMARC correctly on your domain before you send your first real email.