SendGrid vs SparkPost: a smaller bill against a wider platform

Cost at each published volume

Both vendors price by monthly volume and the stops differ, so each row pairs the nearest published volume on each side. SendGrid readouts come from the selector on its Email API pricing page, SparkPost's from the volume table on its pricing page, both read on 7 October 2026.

The yearly column is the monthly gap times 12: ($19.95 - $15) x 12 = $59.40 at 50,000 emails and ($89.95 - $80) x 12 = $119.40 on the top plans at 100,000. Both gaps are small enough to ignore for a young product. The real savings begin at 250,000 emails, where SparkPost's $0.70 per 1,000 sits 13 cents under SendGrid's $0.83 at 300,000; at 500,000 against 700,000 the difference is 12 cents. By a million emails the lines meet, which means a SaaS growing from 100,000 to a million gets the largest advantage in the middle, not at either end.

When you go over the plan

SparkPost's pricing page says the default overage ceiling is five times your plan and sends pause at that ceiling unless you agree different terms. SendGrid's says taxes and overages may apply and does not describe a stop. The practical split: SparkPost caps the damage of a bug that sends the same email in a loop, while SendGrid keeps delivering and sends you the bill. A pause is safer for a cost-sensitive team and riskier for a business whose password resets must never wait. Ask SparkPost to raise the ceiling before a planned spike such as a pricing change announcement to your whole base.

Dedicated IPs and plan limits

• SparkPost. Dedicated IPs cost $24.95 a month each, on Growth only, up to five. Every plan lists 30-day retention and a 20 MB message-size limit.
• SendGrid. The pricing page says Pro and Premier plans include dedicated IPs, with the option to buy more. It does not state how many Pro includes in the text read for this page, so ask before assuming one.

At 100,000 emails with one dedicated IP, SparkPost Growth is $80 + $24.95 = $104.95 a month and SendGrid Pro is $89.95 with IPs included, so SendGrid is $15 a month cheaper for that setup. Without a dedicated IP, SparkPost Startup at $30 beats both. The cheapest honest comparison for a SaaS sending 100,000 emails is therefore SparkPost Startup at $30 on shared IPs, and SendGrid Pro at $89.95 if shared-IP reputation is the concern.

Webhook design and the failure window

SendGrid's Event Webhook reports processed, delivered, deferred, dropped and bounce events plus engagement events, and the page says to use the Signed Event Webhook, OAuth 2.0 or both (SendGrid event docs). SparkPost's webhooks post events in batches. Each batch carries an X-MessageSystems-Batch-ID header, each event an event_id for de-duplication, and your endpoint has 10 seconds to answer. Authentication is set per webhook to none, basic or OAuth2, only ports 80 and 443 are allowed, and any batch not answered with HTTP 200 is retried for 8 hours before it is discarded (SparkPost webhook docs).

SparkPost's event list is the longer one: bounce, delivery, injection, spam_complaint, out_of_band, policy_rejection, delay, click, open, list_unsubscribe, link_unsubscribe and others. Its docs advise saving each batch to disk and processing asynchronously, which suits a billing flow where a failed-payment email must be tracked from injection to delivery. If you want one signed payload per event with a documented key pair, SendGrid's design fits better.

Marketing email and the rest of the account

SendGrid sells Marketing Campaigns separately, with a free plan of up to 2,000 contacts and 6,000 emails a month and paid Basic and Advanced tiers from $15 and $60. SparkPost's pricing page describes email sending plans, and a SaaS that wants newsletters from the same vendor will find SendGrid's route the shorter one. For billing emails the choice has no effect: Stripe's invoice.payment_failed or Paddle's subscription.past_due reaches your server, and your code sends the message through either API.

Which to choose

• Choose SparkPost if you send 100,000 to 500,000 emails a month, want the lowest per-1,000 price and would rather have sending pause at a ceiling than run up a bill.
• Choose SendGrid if you want signed webhooks, dedicated IPs bundled into Pro, a free Marketing Campaigns plan or a trial that lets your team see the product before paying.
• Ask both for a quote above two million emails. SparkPost moves to custom Enterprise rates at 2,500,000 and SendGrid's Pro tops out at $1,099 on the selector, with Premier custom beyond it.

Moving from SendGrid to SparkPost

1. Check the plan name and brand on the page you will sign: SparkPost's address now opens a Bird-branded pricing page.
2. Publish new SPF and DKIM records for a sending subdomain, leaving SendGrid's records in place during the overlap.
3. Export SendGrid's bounces, spam reports and unsubscribes and load them as suppressions on the destination before any send.
4. Rewrite the webhook handler to accept batches, de-duplicate on event_id and answer inside 10 seconds, replacing the ECDSA check with the authentication type you chose.
5. Cut over one message stream at a time, keep payment notices on SendGrid for the first week, and ask for a higher overage ceiling if your volume is spiky.

Related reading: all comparisons, Resend vs SparkPost, Mailgun vs SparkPost, SendGrid vs Postmark and SendGrid vs Mailgun.