XPath Tester — Query XML Elements
Test simple XPath expressions against XML content to find matching elements and attributes.
How it works
- 1Paste or type your text in the input field
- 2Click "Process" — processing happens in your browser
- 3Copy the result or download as a text file
What to do next
About XPath Tester
XPath Tester is the kind of utility you bookmark and reach for when you need it. Test simple XPath expressions against XML content to find matching elements and attributes. It loads quickly, works on any modern browser, and produces a result you can download or copy in a single click.
The processing pipeline is straightforward: your input is parsed by standard browser APIs, transformed according to the options you select, and serialised back into a downloadable result. The 0 MB per-file ceiling matches what a typical browser tab can handle without paging to disk.
The right moment to reach for XPath Tester is when you have a focused developer utility job that fits inside a browser tab. Open the page, drop in the file or paste your input, choose the options that matter, and the tool returns the result.
The architecture is local-first by design. Once the page is loaded, you can disconnect from the network and the tool still completes the job. The processing stack — standard browser APIs and the small UI shell wrapping it — ships with the page itself, so the tool keeps working in offline conditions, on a captive-portal Wi-Fi, or behind a corporate proxy that limits what the tab can reach.
Constraints worth knowing about: inputs are capped at 0 MB to keep memory usage in a sensible range, one input is processed per run, and the tool must be loaded over HTTPS for the in-browser engine to work. These are properties of the architecture.
XPath Tester is intentionally narrow in what it does, which makes it easy to slot into a longer workflow. Take its output, hand it to whichever next tool fits the job, and XPath Tester stays out of your way until the next time you need it.
XPath Tester is shaped around the recurring needs of two audiences: backend developers inspecting requests, who use it as a quick utility between bigger tools, and QA engineers writing repro cases, who use it as their primary way of getting the job done. Both groups get the same defaults and the same speed.
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.
The transformation in XPath Tester is deterministic — the same input plus the same options produces the same result every run. That predictability matters when the result has to match an upstream specification or be reproducible later.
From a product perspective, XPath Tester is one of the simplest possible expressions of "do one thing well." The catalog contains dozens of related tools that each handle a slightly different developer utility task, and every one is a separate page rather than a tab inside a larger app. That separation keeps each tool fast to load and easy to bookmark.
If you want to get the most out of XPath Tester, three small habits help. Drag-and-drop is faster than the file picker once you get used to it. The keyboard shortcut for downloading the result is whatever your browser uses for "save link as," because the result is a normal download. And if you are working on a sensitive file, processing in an Incognito or Private window is a good extra layer — it leaves no trace in browser history when the tab closes.
XPath Tester is built around the moment of need: a focused page you open when you have a specific task, complete the task, and close. The catalog contains many adjacent tools so the same model serves the surrounding parts of a typical developer utility workflow.
When something goes wrong, the cause is usually one of three things: a malformed input, a browser that is out of memory, or a corporate proxy that is interfering with the page's static assets. The first two are easy to diagnose; the third typically requires asking your IT team to allow standard browser APIs to load.
If XPath Tester solved your problem, sharing the page link with someone who has the same problem is the most useful thing you can do. The catalog grows mostly through word of mouth; visitors arriving through a recommendation tend to be the ones the tool serves best.
How it works
- 1Land on the XPath Tester page. The tool is ready to use the moment the page renders.
- 2Select the developer file you want to process — drag-and-drop and the file picker both work.
- 3Tweak the controls if the defaults are not quite right for your input. The options are kept short and labelled in plain language.
- 4Trigger processing. standard browser APIs reads your input, applies the transformation, and writes the result back into the page.
- 5Download the result. The file is generated in your browser and saved through your normal download flow.
- 6Re-run with different settings as often as you want. Each run produces a fresh output and the original file on disk is never modified.
Common use cases
- Pretty-print a minified blob during incident triage using XPath Tester.
- Convert between data formats while wiring up an integration.
- Format a noisy log line into something a teammate can read.
- Inspect a regex against a test string before committing it.
- Decode a token to confirm its claims during a debugging session.
- Validate a config blob before pushing to staging.
- Hash a string for a quick reproducibility check.
- Compare two API responses to spot a regression.
FAQ
How do I enter the XPath?
Put the XPath expression on the first line, then your XML on the following lines.
What XPath syntax is supported?
Simple descendant paths (//tag) and attribute selectors (//tag/@attr). Complex predicates are not supported.
Can I use predicates like [1] or [@id="x"]?
Not in this simplified tester. Use basic //tag and //tag/@attr paths.
What if nothing matches?
The tool reports "No matches found" — check that your tag names match the XML exactly.
Does it support namespaces?
Namespace prefixes are matched literally. Use the full prefixed name as it appears in the XML.
Is my data safe?
All processing happens in your browser.
Is XPath Tester lossless?
XPath Tester 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.
Why did XPath Tester reject my input?
Failures usually fall into one of three buckets: the input is in an unsupported format, the input is over the size cap, or the input is structurally malformed (a truncated download, a partial export, or a stream the engine does not recognise). The first two are easy to confirm — check that your file is in a supported format and that it is below 0 MB. For the third, opening the file in its native viewer first is the fastest way to confirm the source is intact.
Are jobs run with XPath Tester stored anywhere?
Favtoo keeps no copy of your file because Favtoo never receives your file. XPath Tester runs entirely in your browser, the input is held only in your tab's memory, and closing the tab discards it. There is no opt-in cloud history, no "recent jobs" panel synced to an account, and no server-side retention to configure — the architecture simply has nowhere for your file to be stored.
Will XPath Tester ask me to pay to download the result?
XPath Tester is free to use. The processing runs in your browser, which keeps the per-user cost low enough that the tool can be offered openly. The download is the same file the engine produced — you can use it for as many runs as you need.
Does XPath Tester need an internet connection to run?
Once the page is loaded, XPath Tester 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.
How long does XPath Tester take to process a file?
Most jobs finish in seconds. Speed scales with input size and with how many CPU cycles your browser tab has available — the engine runs in your browser, so it shares resources with whatever else you have open. For inputs near the 0 MB ceiling, expect anywhere from a few seconds to roughly a minute on a typical laptop. Closing other heavy tabs noticeably speeds things up.
Is XPath Tester mobile-friendly?
XPath Tester 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 is XPath Tester different from desktop apps that do the same thing?
Desktop apps usually have more advanced features but require installation, maintenance and (often) a licence. Paid online tools are convenient but route your file through their servers and gate downloads behind accounts. XPath Tester sits in between: free, instant, and private, but intentionally narrow in scope. For one-off jobs and the common developer utility operations, it is usually the lowest-friction choice; for highly specialised work, a dedicated app is still the right answer.
Does XPath Tester require a browser extension or plug-in?
No installation is needed. XPath Tester 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 XPath Tester on any computer you have temporary access to without leaving anything installed on it.