Choose Resend if you're a developer or small team who wants a code-first email API, React-built templates and nothing but email. Choose SendGrid if you already use Twilio for texts or calls, want a separate Marketing Campaigns tool, or want a vendor that says it sends at very large volume. Neither wins outright: it comes down to whether email sits on its own or beside other channels.
Type sendgrid.com into a browser today and you won't land on a standalone email company's website. You'll get a notice that the sites were merged and the email products have moved in to Twilio.com, where the vendor says they stay fully supported. That single change reshapes this comparison more than any feature list does.
So you aren't choosing between two email companies any more. You're choosing between an email-only business and one product line inside a large communications platform. For the rest of this page I'll call them the newcomer and the Twilio product, because that's the plainest way to describe each one.
What the merger means for your shortlist
The Twilio product's Email API and SMTP service now sit in the same menu as SMS, WhatsApp, RCS, voice, verification and a customer data platform. If your app already sends texts or makes calls through Twilio, that's a real point in its favour: one vendor, one account relationship and one set of docs to learn. The vendor also says it delivers more than 200 billion emails every month.
If email is the only thing you send, the picture flips. You'd be signing up to a platform whose front door is a Twilio-wide menu, with email as one entry among many. That isn't a flaw in itself, but it does mean the product you're weighing up is shaped by a much bigger business with a dozen other channels to look after.
The newcomer is the opposite story. Its about page says it began as an open source project in 2022, launched its sending platform in 2023 and joined Y Combinator. Everything on its site is about email: sending, testing, webhooks and deliverability.
Feature by feature
| Topic | Resend | SendGrid |
|---|---|---|
| Ownership | Email-only company that started as an open source project | Product line inside Twilio; its own site now points to Twilio.com |
| Developer experience | Code sample up front, SDKs for Node.js, Python, Ruby, PHP, Go, Rust, Java, Elixir and .NET, plus REST and SMTP | Email API and SMTP with documentation, code samples and a developer hub |
| Templates | React-built templates through react-email, an open source component library | Its site doesn't describe a template approach |
| Marketing tools | Visual broadcast editor, contact management and broadcast analytics | Separate Marketing Campaigns product for marketers |
| Other channels | Email only | SMS, WhatsApp, RCS, voice and verification in the same platform |
| Deliverability | Blocklist tracking with removal requests, sending regions on four continents, BIMI support | Vendor claim of proven deliverability at very large volume |
| Testing | Test mode that simulates events without emailing real people | No test mode mentioned |
| Getting started | Not mentioned | Free trial stated |
Writing code against each one
The newcomer's home page opens with a code sample, which tells you who it's built for. It lists SDKs for Node.js, Python, Ruby, PHP, Go, Rust, Java, Elixir and .NET, alongside a REST API and SMTP. If you work in one of the less common languages on that list, such as Elixir, it's helpful to see it named up front.
The Twilio product offers an Email API and an SMTP service with documentation, code samples and a developer hub. Its product page reads as part of the wider Twilio menu rather than leading with code, so there's less to say about it here.
Templates and testing
This is where the newcomer stands out most. Its site says you can build email templates in React with react-email, its open source component library, instead of fighting table layouts and raw HTML. If your front-end team already writes React, that's a big deal, because the people who build your product can also build your emails.
It also has a test mode that simulates events without sending anything to real people, which is handy for staging and automated checks. The Twilio product's site doesn't describe a template authoring approach or a test mode, so ask about both on a sales call if they matter to you.
When marketers share the account
Both vendors have thought about the people who aren't engineers, just in different ways. The newcomer includes a visual editor for broadcasts, contact management and broadcast analytics inside the same product, so someone in marketing can send a newsletter-style email without touching code.
The Twilio product keeps marketing separate. Its Marketing Campaigns tool is listed next to the Email API as its own product for marketers. That suits companies where the marketing team wants a tool with its own name and its own login.
Getting into the inbox
The newcomer lists the most specific deliverability tooling of the two. It states proactive blocklist tracking, with removal requests generated for you, sending from regions in North America, South America, Europe and Asia, and support for BIMI, the standard that lets supporting inboxes show your brand logo next to your messages.
The Twilio product's pitch here is scale. It says it has proven deliverability at very large volume, but its site doesn't break that down into specific tools. If inbox placement is your biggest worry, it's worth pairing either sender with one of the email deliverability tools that monitor inbox placement.
Other email APIs to put on the shortlist
If neither feels right, these four are the closest rivals, each with a different angle on sending. My wider guide to the best email APIs for developers covers more of them in depth.
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Postmark
Best for: Transactional email through an Email API or SMTP, with message streams, inbound email and a vendor-stated focus on fast, reliable delivery.
Mailgun
Best for: Developers wanting an Email API and SMTP relay with tracking, plus email validation and inbox preview tools; the vendor says over 150,000 businesses use it.
Amazon SES
Best for: Teams already inside AWS that want managed sending and receiving through an API or SMTP, with dedicated, shared or owned IP addresses.
Brevo
Best for: Small businesses sending transactional email alongside SMS and WhatsApp, with webhooks, templates and inbound parsing in one platform.
My advice, plus a four-point checklist
Go with the newcomer if you're a developer or a small team who wants a code-first API, React templates, a test mode and a clean product that only does email. Go with the Twilio product if you already use Twilio for other channels or plan to, if your marketers want a separate campaigns tool, or if sending volume on a very large scale is what reassures you. Neither site shows a clear overall winner, so let your other channels decide.
- Do you send anything besides email, or plan to? If yes, the Twilio product earns a closer look.
- Does your front-end team write React? If yes, react-email is a strong reason to try the newcomer.
- Do you need a test mode for staging? Only the newcomer says it has one.
- Will marketers send broadcasts? Decide whether they want a shared editor or a separate tool.
Do you make an email API or sending platform? Tool makers can ask to be considered for a featured place on this page.
Want your tool on this list? Featured spots and reviews here are paid partnerships. Here's how to partner with me.
Related: python: guidelines and how to pitch.
Frequently asked questions
Is SendGrid still its own company?
Its website now says the sites were merged and the products moved to Twilio.com. The email API, SMTP service and Marketing Campaigns stay supported there as part of the Twilio platform.
Does Resend offer SMTP as well as an API?
Yes. It lists REST and SMTP, with SDKs for Node.js, Python, Ruby, PHP, Go, Rust, Java, Elixir and .NET.
Can I build email templates in React?
The newcomer pushes React-built templates through react-email, its open source component library. The Twilio product's site doesn't describe a template approach.
Which one is better if I also send text messages?
The Twilio product, because email sits in the same platform as SMS, WhatsApp, RCS and voice. The newcomer only does email.
Is there a free trial?
The Twilio product states a free trial. Check the newcomer's sign-up page for how it lets you start.
