Online YAML viewer
Open a YAML file in your browser and read it as a collapsible tree or as formatted code, with anchors resolved, indentation mistakes flagged and nothing uploaded to a server.
Open the YAML viewerNo signup. Nothing uploaded.
Why a viewer rather than a text editor
YAML is written by people and read by machines, and the gap between those two is where the bugs live. A manifest that is one space out of alignment is still valid YAML — it just means something different from what you meant. Seeing the parsed structure, rather than the text you typed, is how you catch that.
Ways to read a YAML file
- Tree
- The parsed document, not the source. Anchors and aliases are already resolved, so you see the values a tool will actually receive rather than the references you wrote.
- Code
- Monaco with YAML syntax highlighting, folding by indentation, and anchors and aliases picked out so they are visible at a glance.
- Graph
- The document as a node-link diagram, which makes a deeply nested manifest legible in a way that indentation alone does not.
- Schema
- Validate a YAML document against a JSON Schema — the same schema your CI uses — with errors underlined in the source.
What people use it for
- Kubernetes manifests
- Check what a manifest resolves to before applying it. The tree shows the merged result of your anchors, which is what the cluster will see.
- CI pipeline definitions
- GitHub Actions, GitLab CI and CircleCI configs nest deeply. Collapse the jobs you are not debugging and read the one you are.
- Docker Compose
- Convert a Compose file to JSON to feed a tool that expects it, or compare two versions structurally to see what actually changed between them.
- Application config
- Spot the mixed tabs and spaces, the alias pointing at an anchor that no longer exists, and the key that is silently a string when you meant a number.
What it checks in your YAML
- Parse errors reported at the line and column where they occur
- Mixed tab and space indentation, which YAML forbids and many editors hide
- Aliases pointing at anchors that are never defined
- Optional JSON Schema validation against the parsed document
Privacy
The file is read by your browser and parsed on your own machine. No request carries its contents — you can confirm that in your browser's network panel, or by disconnecting from the network and using the app anyway. There is no account, and nothing is stored on a server because there is no server.
File types it opens
.yaml, .yml — and any file you paste, whatever its name. Up to 50 MB by default, adjustable to 500 MB in Settings.
Questions
How do I view a YAML file online?
Open fileviewer.dev and drop a .yaml or .yml file onto the page, or paste YAML text. It is parsed in your browser and shown as a tree with anchors resolved, or as syntax-highlighted code.
Does the viewer resolve YAML anchors and aliases?
Yes. The tree and graph views show the parsed document, so anchors are already expanded to their values — which is what a tool consuming the file will see. Converting to JSON expands them permanently, and the conversion says so.
Can I use it for Kubernetes manifests?
Yes. Multi-document manifests, deep nesting and anchor-heavy Helm output all parse. You can also validate a manifest against a JSON Schema and see the errors underlined in the source.
Is my YAML uploaded anywhere?
No. Parsing happens in your browser. Nothing about the file is sent anywhere, which matters more for YAML than for most formats — configuration files are exactly where credentials tend to sit.
Can I convert YAML to JSON?
Yes, and that pair is lossless for the data: anchors are expanded and comments are dropped, but every value survives. The conversion panel states that explicitly before you run it.