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APIs · head to head

Basis Theory vs Svix

Basis Theory logo

Basis Theory

APIs

Developer tokenisation platform that holds card and sensitive data inside a PCI Level 1 environment you do not operate

From
$995/month
Rated
-
Full reviewWebsite
Svix logo

Svix

APIs

Outbound webhook sending as a service, with retries, signing and a customer-facing portal

From
Free
Rated
-
Full reviewWebsite

The short version

  • Only Svix has a free tier, so it costs nothing to try first.
  • Each has a real cost: Basis Theory the Starter plan is 995 US dollars a month before any volume, which is a real floor for an early stage company and puts the product out of reach of teams tokenising a few thousand records.; Svix the Professional tier at 490 US dollars a month includes the same 50,000 messages as the free tier, so the upgrade buys SLA, throughput and retention rather than volume, which is a jarring step for a growing product.
  • They diverge on capability: Basis Theory covers Tokenisation API, Svix covers Automatic retries.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Basis Theory and Svix actually diverge.

Attributes where Basis Theory and Svix differ
AttributeBasis TheorySvix
Starting price$995/monthFree
Pricing modelPer month by token volumePer month by message count
Free tierNoYes
PlatformsWeb, iOS, Android, LinuxWeb, Cloud, Docker

Identical on both: user rating (Not yet rated), category (APIs).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Basis Theory

  • Tokenisation API
  • Hosted elements
  • Outbound proxy
  • PCI attestation of compliance
  • Processor portability
  • Reactors
  • Access controls and audit
  • PII and PHI options

Only in Svix

  • Automatic retries
  • Payload signing
  • Consumer portal
  • Event types and filtering
  • Delivery logs and replay
  • Rate limiting
  • Static source IPs
  • Language SDKs

What people use each for

The jobs each tool is most often brought in to do.

Basis Theory

  • A payments company that wants card on file without bringing its own infrastructure into PCI scope and paying for the assessment that followsnot Svix
  • A merchant locked into a processor by that processor vault that wants to hold its own tokens and route to more than one acquirernot Svix
  • A fintech collecting bank account and identity data that needs it isolated from its application database before an enterprise security reviewnot Svix
  • A team that needs to send stored card data to a third party for a one-off integration without that data traversing its own serversnot Svix

Svix

  • A SaaS company adding webhooks to its API that does not want to build retry, signing and a customer debugging UI from scratchnot Basis Theory
  • A payments or fintech product whose customers need signature verification libraries in several languages they did not writenot Basis Theory
  • An engineering team drowning in support tickets from customers whose endpoints silently failed and who need self-service delivery logsnot Basis Theory
  • A platform with a small number of very slow customer endpoints that must not delay deliveries to everyone elsenot Basis Theory

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Basis Theory

  • The Starter plan is 995 US dollars a month before any volume, which is a real floor for an early stage company and puts the product out of reach of teams tokenising a few thousand records.
  • Starter is limited to the US region, so a company with European data residency requirements is pushed into a quoted Scale or Enterprise agreement immediately.
  • Log retention on Starter is 24 hours, which is well below what most security teams expect for a system holding cardholder data and forces an upgrade for reasons unrelated to volume.
  • Migrating away means moving card data out of the vault, which requires processor and assessor involvement and is slow, so the portability argument that attracts buyers cuts against them at exit.
  • An attestation of compliance covers the vendor environment, not your assessment; your assessor still decides what is in scope, and buyers occasionally discover their integration pattern pulled systems back into scope anyway.

Svix

  • The Professional tier at 490 US dollars a month includes the same 50,000 messages as the free tier, so the upgrade buys SLA, throughput and retention rather than volume, which is a jarring step for a growing product.
  • Only attempted messages count toward usage, but a customer with many subscribed endpoints multiplies a single event into many billable messages, and forecasting that fan-out before launch is difficult.
  • The open source server is MIT licensed but trails the hosted product in features, so self-hosting is a fallback position rather than a genuinely equivalent option.
  • Routing outbound customer traffic through a third party puts a vendor in the delivery path for events your customers may treat as contractual, which some security reviews will not accept.
  • Payload retention is 30 days on the free tier and 90 on Professional, so anyone needing longer delivery history for audit must pay for Enterprise or log independently.

Pricing, plan by plan

Basis Theory

$995/month
  • Starter$995/month
    • 20,000 tokens included
    • Production PCI Level 1 environment
    • US region only
  • Scale$undefined/month
    • Quoted
    • Higher token volumes
    • Additional regions
  • Enterprise$undefined/month
    • Quoted
    • Additional compliance options for PII and PHI
    • Responses for 95 percent of PCI SAQ D

Svix

Free
  • FreeFree
    • 50,000 messages a month included
    • Overage at $0.0001 per message
    • 99.9% uptime SLA
  • Professional$490/month
    • 50,000 messages included, same as free
    • 99.99% uptime SLA
    • 800 messages per second
  • Enterprise$undefined/year
    • Custom volume and rate limits
    • 99.999% uptime SLA
    • Custom retention

Which should you pick?

Choose Basis Theory if

  • You need tokenisation api.
  • You work on Web, iOS, Android, Linux.
  • You also want hosted elements.
Basis Theory review

Choose Svix if

  • You need automatic retries.
  • You want to start without paying.
  • You work on Web, Cloud, Docker.
  • You also want payload signing.
Svix review

Questions people ask

Is Basis Theory or Svix better?
Neither clearly leads. Basis Theory starts at $995/month and Svix at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Basis Theory or Svix?
Svix has a free tier; the other does not. Paid plans start at $995/month for Basis Theory and Free for Svix.
Does Basis Theory or Svix run on more platforms?
Basis Theory runs on Web, iOS, Android, Linux. Svix runs on Web, Cloud, Docker.
Can I use Svix for free?
Yes. Svix has a free tier, so you can try it without paying. Basis Theory starts at $995/month.
What is Basis Theory best used for?
Basis Theory is most often used for a payments company that wants card on file without bringing its own infrastructure into pci scope and paying for the assessment that follows, a merchant locked into a processor by that processor vault that wants to hold its own tokens and route to more than one acquirer, a fintech collecting bank account and identity data that needs it isolated from its application database before an enterprise security review, a team that needs to send stored card data to a third party for a one-off integration without that data traversing its own servers. Of those, a payments company that wants card on file without bringing its own infrastructure into pci scope and paying for the assessment that follows and a merchant locked into a processor by that processor vault that wants to hold its own tokens and route to more than one acquirer are not what Svix is typically brought in for.
What can Basis Theory do that Svix cannot?
Basis Theory covers Tokenisation API, Hosted elements, Outbound proxy, PCI attestation of compliance. Svix covers Automatic retries, Payload signing, Consumer portal, Event types and filtering.

Answered from the vendors’ own pages

Basis Theory: Does this make us PCI compliant?

It removes cardholder data from your systems and gives you an AOC plus documented responses for most of a SAQ D. Your assessor still determines your scope, and a careless integration can pull systems back in.

Svix: How much does Svix cost?

Free up to 50,000 messages a month; Professional starts at 490 US dollars a month with the same included volume but better SLA and throughput.

Basis Theory: What does it cost to start?

995 US dollars a month on Starter, including 20,000 tokens, a production PCI Level 1 environment and US hosting. Higher tiers are quoted.

Svix: Can I self-host it?

Yes, there is an MIT licensed server, but it lags the hosted service in features and has no SLA.

Basis Theory: Can we switch payment processors without re-collecting cards?

Yes, that is the main non-compliance reason to buy it. You hold the tokens and detokenise into whichever processor you route to.

Svix: What counts as a message?

Attempted or transformed deliveries. Retries and messages filtered out because no endpoint subscribed are not charged.

Basis Theory: Is data stored outside the United States?

Not on Starter, which is US only. Other regions require a Scale or Enterprise agreement.

Svix: Does it handle inbound webhooks?

Its focus is outbound sending on behalf of API providers, not receiving webhooks from third parties.

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