Fact checking software for newsletters: keep the archive right after you hit send
Most fact checking software for newsletters stops at the draft. But your issues live on as web pages that get indexed and shared for years. Veritas reads your newsletter's RSS feed or sitemap, re-checks the claims in past issues and flags the ones that have gone out of date.
Key takeaways
- A sent email can't be changed, but the web archive can, and it's what search engines index.
- Substack, beehiiv and Ghost publish RSS feeds, which is how Veritas finds your past issues.
- AI-writing detectors say who wrote a post, not whether its claims are true.
A newsletter has two lives. The email goes out once and can't be changed. The web version stays online, gets crawled by search engines, and is what people find when they search a topic or follow a link months later.
That makes the archive the part worth keeping accurate. This guide covers how each major platform handles edits after sending, why AI-writing detectors are not fact checkers, a corrections routine that works for a one-person newsletter, and where Veritas fits. Platform details come from each platform's own help pages, checked in October 2026.
The sent email is frozen; the web archive isn't
Here is what each platform's own help pages say about changes after sending. The pattern is the same wherever the docs are clear: you can fix the web copy, not the email in subscribers' inboxes.
Its editor guide says a post can only be emailed once, and edits to a published post show only on the web.
When you publish to both email and web, edits made after the send appear only on the web version. During a scheduled A/B test, the web version can't be edited until the test ends.
Lets you change a link in an already-sent newsletter from the post's analytics, provided click tracking is on.
A broadcast published to the web goes live once the email has finished sending, and a sent broadcast can be made public later.
The web copy is also found fast. Substack's SEO team reported in February 2023 that the median time from publishing to a Google crawl had fallen to 3 hours. Whatever is in the archive is what searchers read.
What goes stale in a newsletter archive
Newsletters are dense with facts that have a shelf life:
That publish a newer edition each year.
That reads as current to someone landing on the issue a year later.
In market, finance and startup newsletters.
A chief executive, a minister, a team's coach.
"the largest", "the first", "the only".
That keep getting traffic long after the news that prompted them.
None of this was wrong on send day. It becomes wrong while the issue sits in the archive.
AI-writing detectors are not fact checkers
Search for an AI fact checker for Substack in 2026 and the results are mostly news coverage of Substack's AI-writing detector, built with Pangram. A detector like that estimates whether text was written by an AI model. It says nothing about whether the claims in the text are true.
The two problems are separate. A carefully hand-written issue can quote a statistic that was replaced last month, and an AI-assisted issue can be entirely accurate. If accuracy is the goal, you need a tool that checks claims against evidence.
What fact checking tools exist for newsletter writers
No tool in the results for this search is built for newsletters specifically. The options fall into three groups:
Such as Originality.ai's fact checker, Manus and FactSentinel. You paste a draft or a URL, and each claim gets a label or verdict with sources. Useful before sending.
Such as Letterhead's email content check, which looks at links and image alt text before you send. It checks delivery and rendering, not facts.
Such as Google Fact Check Explorer for claims that fact-checkers have already examined, and reverse image search for pictures.
All of these work on one draft at a time, before it goes out. None of them describes re-checking your back issues after they are published.
See which facts on your site have gone out of date.
Request early accessHow Veritas checks your newsletter archive
Veritas is an autonomous fact-maintenance agent that runs in the cloud on a schedule. Newsletters already publish the two things it needs to find your issues: an RSS or Atom feed, and often a sitemap.
Veritas reads RSS and Atom feeds, sitemaps and sitemap indexes. Substack serves a feed at /feed, beehiiv offers an RSS feed on all plans, and Ghost generates RSS feeds and XML sitemaps automatically.
Statistics, dates, who holds a role, quotes attributed to named people, events, comparisons and superlatives. It skips opinion and prediction, so your analysis and takes are left alone.
Prefers primary sources such as statistics offices and official records, and lets you list the sources you trust.
Supported, contradicted, outdated, misleading or unverifiable. "Outdated" means it was true when sent and isn't now.
Each with evidence, citations and a suggested rewrite you can apply in one click. Time-sensitive claims are re-checked on a schedule, and unchanged ones are never re-checked twice.
There is also a pre-publish check for drafts, so the same tool can check an issue before it goes out. One caution: Veritas reads the HTML a page serves, so archive pages need to show their text without JavaScript.
A corrections routine for a one-person newsletter
Solo writers have published simple, transparent policies worth copying. The Faked Up newsletter strikes through errors rather than deleting them, because a sent email can't be taken back, adds a note at the top of the next issue, and keeps a public corrections log. Case by Case keeps a public document of corrections with in-line edits and endnotes.
A routine that fits a weekly cadence:
Run the draft through a pre-publish check and confirm every number against its original source.
Look at flagged claims from past issues, most-read issues first.
Strike through or update the sentence, add a dated note saying what changed, and link the newer source.
If the error was significant, say so at the top of the next issue.
A public page listing corrections builds trust and makes the archive's history clear.
Outdated is not the same as wrong. If a figure was right when sent and has since changed, an update note is usually more honest than a correction.
Platform notes before you connect a tool
Feeds live at /feed. Not every publication has a sitemap; Substack's own on.substack.com returns "This publication does not have a sitemap", while other publications do have one. The feed is the reliable entry point.
Turn on the RSS feed in settings. Regenerating it creates a new feed URL, so update any tool that reads it.
RSS lives at /rss/, with feeds for tags and authors too, and the XML sitemap is linked from robots.txt. A private site's feed isn't public.
Publish broadcasts to your newsletter feed page to give them a web home. We couldn't find official RSS output from Kit, so check your own publication's options.
For the wider problem of stale pages on any site, see our guide to outdated content detection.
Honest limitsWhen Veritas isn't the right fit
A paste-in fact checker does that job, and Veritas's pre-publish check is one option among several.
With no web archive: there is nothing for Veritas to re-check.
Use an AI-writing detector; Veritas checks claims, not authorship.
Veritas reads the HTML a page serves.
Read more about Veritas or how it works for journalists.
How Veritas works
- Finds your pagesReads your sitemaps, Google News sitemaps and RSS or Atom feeds on a schedule.
- Pulls out the claimsStatistics, dates, who holds a role, quotes, events. Opinion is skipped.
- Checks the evidenceSearches outside your site and prefers primary sources.
- Hands editors the fixConfident findings only, with citations and a one-click rewrite.
Frequently asked questions
Can I edit a newsletter after it's sent?
You can edit the web version but not the email already delivered. Substack and beehiiv both say edits after sending appear only on the web. Ghost also lets you change links in a sent newsletter if click tracking is on.
Is Substack's AI detector a fact checker?
No. It estimates whether a post was written by AI. It doesn't check whether the claims in the post are true.
How do I correct a newsletter that has already gone out?
Fix the web copy with a dated note or a strike-through, mention significant errors at the top of your next issue, and keep a public corrections log. Some solo newsletters publish policies along these lines.
Can Veritas read my Substack or beehiiv archive?
Veritas finds pages through RSS and Atom feeds, sitemaps and sitemap indexes. Substack serves a feed at /feed and beehiiv offers an RSS feed on all plans. Veritas reads the HTML each page serves, so archive pages need to show their text without JavaScript.
Will Veritas change my opinions or analysis?
No. Veritas skips opinion and prediction and checks only factual claims such as statistics, dates, roles, quotes, events, comparisons and superlatives.
How often should old issues be re-checked?
It depends on the claim. Veritas re-checks fast-moving claims after 7 days, slowly decaying ones after 45 and stable ones after 365, and never re-checks a claim that hasn't changed.
Keep every page true
Veritas re-checks the facts across your published pages and hands editors a sourced fix when one goes stale.
Request early access12 sources, checked 30 October 2026
- Substack: How to use the Substack editor
- Substack: The state of SEO on Substack (15 Feb 2023)
- beehiiv: How to create and publish a post
- beehiiv: How to enable and use RSS
- Ghost: Where can I find my RSS feed? (2024)
- Ghost: Updating links in sent newsletters (2025)
- Ghost: XML sitemaps
- Kit: Creating, sending and sharing broadcasts (2026)
- Kit: Newsletter feeds (2026)
- Faked Up: Corrections policy (2024)
- Case by Case: Ethics, accountability and corrections (2022)
- Letterhead: Email content check agent