Free, no account needed
RSS feed validator
Paste a feed address and Inoreader fetches it the way a feed reader does, checks everything a reader needs from it and tells you what to change. The validator is free and you do not need an account.
What the report covers
Syntax is the last thing that breaks a feed. The report starts where readers start: can the feed be fetched at all.
Delivery
The status, redirects, time to answer, bot protection, caching headers, compression and the certificate.
Document
The encoding, well-formed XML, the format and its required elements, and every repair Inoreader had to make before it could read the feed.
Items
The ids, dates, links, images and enclosures, judged by what a reader can show and keep track of.
Real-time
Whether the feed declares a WebSub hub, so readers get new posts within seconds instead of at their next check.
Most broken feeds are valid
Inoreader fetches three million feeds a day, so we see what actually breaks them. Of the feeds that stopped working on one day in October 2026, almost all were still well-formed. The server refused the request, timed out or answered with a web page instead of the feed. A syntax check does not see any of that. This report does.
Feeds that stopped working on one day in October 2026.
Common fixes
Every report row ends with what to change. These fixes come up on most feeds.
Each of these is explained at length, with a complete feed to copy, in an RSS feed example, explained. How posts reach readers within seconds instead of at their next check is explained in WebSub for publishers.
Answer conditional requests
Send an ETag or a Last-Modified header and answer 304 Not Modified when nothing has changed. Otherwise every reader downloads the whole feed on every check.
Let feed readers through
A feed reader cannot solve a bot challenge. Allow verified bots, or the Feed Fetcher category, in the firewall rules.
Keep one id per post
Give every item its own guid and keep it when the post is edited. Without a stable id, readers show every edit as a new post.
Put images in src
Lazy-loaded pictures live in data-src. Readers do not run JavaScript, so they show a blank where the picture should be.
Declare the encoding that is served
The XML declaration and the HTTP header should agree, and both should say UTF-8.
Print nothing before the declaration
A blank line, a PHP warning or a byte order mark before the XML declaration makes strict readers reject the whole feed.
For feeds Inoreader already follows
When the feed you check is one that readers in Inoreader follow, the report adds what the last two days of checks saw: how often Inoreader checks the feed, how many checks the server answered, how many came back 304 Not Modified, how many new articles were found, and every failure with its cause. A feed that broke on Tuesday night and recovered on its own shows up here, where its publisher would otherwise only hear about it from readers.
Frequently Asked Questions
Does a feed have to be valid to work?
No. Inoreader repairs many broken feeds before reading them, and the report lists every repair it made. Other readers may not repair them, which is why the report counts a repair as a warning.
Why does a feed work in one reader and not in another?
Readers differ in what they repair, how long they wait for an answer and which addresses they fetch from. The report marks the checks where readers behave differently, so the feed can be made to work in all of them.
Why do old posts show up as new?
The item ids changed, or every item carries the same id. The Items section of the report shows the ids and what readers do with them. Give every item its own guid or id and keep it when the post is edited.
What does "works, with repairs" mean?
The document is not well-formed XML as published, and Inoreader fixed it before reading it. Readers that do not repair feeds reject it, so the repairs are worth making at the source. An RSS feed example, explained shows what a feed that needs no repair looks like.
Can I check a feed that is not online yet?
Not yet. The validator fetches the feed from the address you give it, because the delivery checks are half the report.
Is the feed validator free?
Yes. It is free and needs no account. If you want to follow the feed, an Inoreader account is free too and holds up to 150 feeds.