Atom Feed Validator
Validate Atom feed XML structure, required elements, and display feed metadata.
How it works
- 1Paste or type your text in the input field
- 2Click "Validate" — processing happens in your browser
- 3Copy the result or download as a text file
What to do next
About Atom Feed Validator
Atom Feed Validator is a self-contained developer utility workspace. Validate Atom feed XML structure, required elements, and display feed metadata. Open the page, get the result, close the tab — that is the entire workflow.
Atom Feed Validator runs on standard browser APIs — an open-source, well-audited engine that performs the developer utility natively in the browser. It accepts the formats listed in the upload area and produces output that opens in any standard developer viewer. Per-run input is capped at 0 MB.
Most people land on Atom Feed Validator via a search at the moment they actually need the tool. That shapes the design: the page is a single screen with the input on one side, the controls in the middle, and the result on the other, so a first-time visitor can complete the job without reading documentation.
The browser sandbox isolates the page's JavaScript from the rest of the system, the same way it isolates every other tab you have open. Atom Feed Validator works inside that sandbox: it reads the file you give it, processes it with standard browser APIs, and writes the result back. Nothing leaves the page's memory unless you choose to download or copy it.
The 0 MB ceiling on input size is the only fixed limit. Output files are produced in standard formats that every common viewer recognises, and the tool runs the same way regardless of how many times you have used it during the session.
Atom Feed Validator sits in a small group of related tools. Useful neighbours include RSS Feed Validator, JSON Feed Validator, XML Sitemap Parser, and robots.txt Tester. They are designed to compose: the output of one is a sensible input to the next, so a multi-step task is usually a sequence of single-click operations.
Common audiences for Atom Feed Validator include QA engineers writing repro cases and devops engineers crafting one-liners, but plenty of people land on the page through a one-off search and never come back — that is also fine. The tool is built to be useful even when you only ever need it once.
Once the engine finishes, the output is offered as an immediate download. There is no preview gate, no email-wall, and no "register to download" intermediary — the file is yours the moment it is ready.
Some notes on the design of Atom Feed Validator. The page is intentionally narrow: one input, the controls relevant to the task, and one output. Adding unrelated features would make the common case slower for the majority of users, so the surface is held to what people actually use.
Atom Feed Validator is one example of a broader pattern: utility software increasingly works as single-page, client-side experiences. Every page in the catalog is shaped that way, which keeps each tool fast to load and easy to recommend in a single link.
Tips from users who reach for Atom Feed Validator regularly: process one input first to confirm the settings produce what you expect before committing to a batch; treat the page as the working surface and avoid leaving large jobs running in a backgrounded tab where the browser may throttle JavaScript; and if a particular file fails, check whether the source is intact by opening it in its native viewer — most "tool errors" are actually input errors.
Atom Feed Validator runs as a regular web page, so there is no install step or permission grant before the first run. The page can be audited by viewing the source or by watching the developer-tools Network tab while a job runs.
For most failure modes, refreshing the page and re-running the job is enough — the engine has no persistent state to corrupt. If the same input fails twice in a row, the input itself is most likely the problem (a truncated file, an unexpected variant of the format, or a stream the engine does not recognise).
That is the whole tool. Use Atom Feed Validator for as long as it stays useful to you, and if it does, the catalog has many more tools built the same way. Each applies the same single-purpose discipline, so the way you used this page transfers to the next one you try.
How it works
- 1Land on the Atom Feed Validator page. The tool is ready to use the moment the page renders.
- 2Add your developer input by dropping it onto the page or browsing for it.
- 3Adjust the options to match what you need. Sensible defaults cover the most common case, so you can usually skip this step.
- 4Click to start the job. The engine (standard browser APIs) processes the input in the page; you can watch the progress indicator until it completes.
- 5Download the result. The file is generated in your browser and saved through your normal download flow.
- 6Run additional jobs as needed. The same controls and defaults apply on every run.
Common use cases
- Encode binary content for transport in a JSON body using Atom Feed Validator.
- Decode a token to confirm its claims during a debugging session.
- Inspect a regex against a test string before committing it.
- Hash a string for a quick reproducibility check.
- Pretty-print a minified blob during incident triage.
- Generate a quick fixture without leaving the browser.
- Validate a config blob before pushing to staging.
- Inspect a payload during local development without writing a script.
- Generate boilerplate from a single specification line.
FAQ
What Atom version?
Validates Atom 1.0 (RFC 4287) — the standard Atom syndication format.
Required elements?
Feed must have id, title, and updated. Entries need id, title, and updated.
Atom vs RSS?
Atom is more strictly defined than RSS, with required dates and unique IDs.
Content types?
Checks content type attributes (text, html, xhtml) on title and content elements.
Author requirements?
Warns if feed or entries lack author elements (recommended by the spec).
Private?
Yes — validation runs locally.
Will Atom Feed Validator keep working if my Wi-Fi drops mid-task?
Once the page is loaded, Atom Feed Validator can complete jobs without an active internet connection — the engine is bundled with the page, so there is no per-job network call. The initial page load does require a connection (to fetch the static assets), but after that you can disconnect entirely and the tool will still work. This is a side-effect of the local-first architecture, not a deliberate "offline mode" feature.
Does Atom Feed Validator work on a phone or tablet?
Atom Feed Validator runs in any modern mobile browser — Safari, Chrome, Firefox and the in-app browsers in most messaging apps all support the underlying APIs. Performance depends on the device: a recent phone handles typical inputs nearly as fast as a laptop, while older devices may take a few seconds longer near the 0 MB ceiling. The interface lays out cleanly on small screens, so you do not need to pinch-zoom to see the controls.
How accessible is the Atom Feed Validator interface?
Atom Feed Validator uses native HTML controls wherever possible, which means keyboard navigation, focus rings, and screen-reader labels work the way the platform expects. The drop zone accepts files via the keyboard-accessible file picker as well as drag-and-drop, and result downloads use standard browser download flows. If you spot an accessibility gap, Favtoo treats it as a bug worth fixing.
Can I self-host Atom Feed Validator for my team?
Atom Feed Validator is a static page running an open-source engine in your browser, so a typical corporate firewall does not get in the way as long as it allows JavaScript to load from Favtoo. For teams that need to host it themselves on an internal network, the underlying engine (standard browser APIs) is open-source and can be packaged into a private build with the same behaviour. Reach out via the Contact page if that is something you are exploring.
Is Atom Feed Validator lossless?
Atom Feed Validator is built to preserve quality wherever the underlying developer format allows it. Operations that are mathematically lossless (e.g. structural transformations, lossless re-encoding) round-trip with no perceptible change. Operations that involve a lossy codec inevitably introduce small artefacts at the byte level, but the defaults aim at the sweet spot where output looks or sounds the same to a normal viewer or listener while still being meaningfully smaller or faster than the input.
Does Atom Feed Validator support batch processing?
Atom Feed Validator processes one input at a time by design — it keeps memory usage predictable on lower-end devices and makes results easier to verify. To handle a folder, run the tool once per file; the page stays loaded between runs and remembers your last-used settings, so the second run is essentially instant.
Do I need to install anything to use Atom Feed Validator?
No installation is needed. Atom Feed Validator runs as a normal web page, with no browser extension, no native helper, and no separate desktop client to download. That is partly a privacy choice — extensions can request broad permissions, while a regular page is sandboxed by default — and partly a convenience one: you can use Atom Feed Validator on any computer you have temporary access to without leaving anything installed on it.