SPF Record Generator

Build SPF DNS TXT records for your domain.

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Input
Output
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About spf record generator

SPF Record Generator keeps its state in memory and nowhere else. That is why it forgets everything on reload, and why it cannot leak anything.

Once the page has loaded it needs nothing further from the network. Work on a plane, on a train, or behind a firewall that blocks everything.

You will find it under Email, alongside 6 other tools for the same sort of job.

Supports Google Workspace, Microsoft 365, Mailgun, SendGrid, Amazon SES, custom IPs, and DNS lookup counting.

How to use it

01
Start it
Every control is on the tool itself. Keyboard shortcuts, where there are any, are listed beside it.
02
Watch it run
It updates in the page as you go. Nothing is sent anywhere, so it keeps working with the network off.
03
Close when done
Nothing is stored between visits. Reloading gives you a clean start rather than picking up where you left off.

Examples

Google Workspace + SendGrid SPF
Generate an SPF record for a domain using Google Workspace and SendGrid
Input
domain: example.com
includeGoogle: true
includeSendgrid: true
policy: ~all
Output
DNS TXT Record for example.com:

  Name: example.com
  Type: TXT
  Value: v=spf1 include:_spf.google.com include:sendgrid.net ~all

Policy explanation:
  ~all (softfail): Emails from unauthorized senders are marked but not rejected

DNS lookup count: 2/10 (SPF allows max 10 DNS lookups)

Questions

Does SPF Record Generator work offline?+

Yes. It is JavaScript running in this tab, so once the page has loaded it needs nothing further from the network. Put the machine in flight mode and it carries on. Nothing you do here is sent anywhere, because there is nowhere for it to go.

Does it remember anything between visits?+

No. Reload the page and it starts from nothing. There is no account, no saved state and no cookie holding your last session. That is a deliberate trade: it cannot lose your data because it never keeps any.

Is it accurate?+

Timing comes from performance.now(), the high resolution clock the browser provides, rather than from setInterval, which drifts by a few milliseconds every tick and compounds over minutes. What can still shift things is the browser throttling a tab in the background, so leave it visible if the timing matters.

Does it make a sound?+

Where a sound makes sense, it is generated with the Web Audio API rather than loaded as a file, so there is nothing to download and nothing to block. Browsers refuse to start audio until you have interacted with the page, which is why the first press is what switches it on.

Can I use SPF Record Generator on a phone?+

Yes. The controls are sized for touch and the layout collapses to one column on a narrow screen. Bear in mind that a phone locking its screen will suspend the page, and timing stops with it.