HTML Formatter — Pretty Print
Format and indent HTML with customizable indentation (2 spaces, 4 spaces, or tabs).
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 HTML Formatter
HTML Formatter is the kind of utility you bookmark and reach for when you need it. Format and indent HTML with customizable indentation (2 spaces, 4 spaces, or tabs). It loads quickly, works on any modern browser, and produces a result you can download or copy in a single click.
The heaviest users of HTML Formatter tend to be site reliability engineers triaging logs, devops engineers crafting one-liners and data analysts wrangling JSON. Each group brings slightly different expectations to the tool, but the same single-page architecture serves every one of them with the same response time.
HTML Formatter performs the transformation entirely inside the JavaScript runtime. Your file lives in the tab's memory while the engine works on it; the result lives in the tab's memory until the browser triggers the download. Both are released when the tab closes, the way every browser tab releases its memory.
From a technical standpoint, HTML Formatter is JavaScript and standard browser APIs running in your tab. The browser is the runtime; the page is the interface. Maximum input size: 0 MB per run.
Most people land on HTML Formatter 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.
For multi-step jobs, HTML Formatter sits next to HTML Minifier, HTML Validator, and HTML to JSX Converter. None of them depend on each other — you can use HTML Formatter on its own — but together they cover the common variations of the task this page exists to handle.
The output handed back by HTML Formatter is the output file. If you would prefer to keep the result in the browser instead of downloading it, you can copy it from the result panel and paste it directly into another tab — useful when the next tool in your workflow expects pasted text rather than a file.
The only practical limit is the 0 MB per-file ceiling, which keeps the tool responsive across a wide range of devices. Run the tool ten times in a row, run it ten thousand times — it behaves the same way and produces the same quality of result.
Some notes on the design of HTML Formatter. 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.
Some context on why HTML Formatter exists in this form: modern File APIs, high-performance JavaScript engines, and well-maintained open-source libraries now make it possible to perform developer utility work entirely in the browser. HTML Formatter is built on top of that capability, which is why a single page can host the full pipeline.
Pro tip: HTML Formatter works just as well in a private/incognito window as in a normal one, which is occasionally useful when you want zero browser-history footprint of the job. Another tip: if the tool ever feels slow, it is almost always because the browser tab is competing for CPU with another tab — pausing or closing the heavy ones gives the engine room to work.
If the result is not what you expected, the most common causes are easy to check. Confirm the input is under the 0 MB ceiling — files just above the cap fail silently because the engine refuses to allocate the buffer. Confirm the input is one of the supported formats. And if the page itself feels slow, try closing other heavy tabs to free up memory; the engine runs in your browser, so it competes for the same resources as everything else open.
HTML Formatter produces deterministic output: the same input plus the same options always produces the same result. That predictability matters when the result has to match an upstream specification or be reproducible later.
HTML Formatter is one of many single-purpose tools in the catalog. Each is built around the same single-page model. Use this one, close the tab, and come back the next time you need the same job done. None of the tools require prior knowledge of the others — each page is self-contained.
How it works
- 1Open the HTML Formatter workspace above. The interface is a single page, so there is nothing to navigate.
- 2Add your developer input by dropping it onto the page or browsing for it.
- 3Pick any non-default settings you need. Most users leave the defaults alone for the first run and only revisit if the result needs tuning.
- 4Trigger processing. standard browser APIs reads your input, applies the transformation, and writes the result back into the page.
- 5Grab the output as soon as the run completes. You can also copy the result instead of downloading if the next tool in your workflow accepts pasted input.
- 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 HTML Formatter.
- Hash a string for a quick reproducibility check.
- Convert between data formats while wiring up an integration.
- Format a noisy log line into something a teammate can read.
- Pretty-print a minified blob during incident triage.
- Inspect a payload during local development without writing a script.
- Compare two API responses to spot a regression.
- Inspect a regex against a test string before committing it.
- Generate boilerplate from a single specification line.
FAQ
What indentation options are available?
2 spaces (default), 4 spaces, or tabs.
Does it handle void elements?
Yes — void elements like <br>, <img>, <input> are recognized and do not add nesting depth.
Will it change my HTML semantics?
No — only whitespace and indentation are changed. Element order and attributes are preserved.
Does it handle inline elements?
All elements are placed on separate lines. Inline text content stays on its own line.
Can I format partial HTML?
Yes — it works with fragments, not just complete documents.
Is my data safe?
All processing happens in your browser.
Does HTML Formatter reduce quality of the result?
HTML Formatter 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 HTML Formatter work with screen readers?
HTML Formatter 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.
Does HTML Formatter support batch processing?
HTML Formatter 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.
Is there a programmatic version of HTML Formatter?
HTML Formatter is a browser-only tool by design and does not expose a hosted API. The reason is the same as the privacy story: there is no Favtoo backend doing the work, so there is no service to call. If you need to script the same transformation, the underlying engine (standard browser APIs) is open-source and can be used directly from your own code.
Why did HTML Formatter 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 there any restrictions on using HTML Formatter at work?
HTML Formatter can be used for personal and commercial work alike — there is no separate "business" licence to purchase. The output you generate is yours to use however you want, including in client deliverables, internal documents, or commercial products. Favtoo's only ask is fair, individual use; the tool is not designed to be embedded as a backend service or wrapped behind an API for resale.
Which browsers are supported by HTML Formatter?
HTML Formatter works in any modern browser released in the last few years — Chrome, Edge, Firefox, Safari, Brave, Arc and the major Chromium derivatives are all supported. The underlying engine relies on widely-supported web APIs, so there is nothing exotic to install. If you are on a very old browser version and the tool fails to load, updating to the latest release of your preferred browser is the only fix needed.
What permissions does HTML Formatter need to function?
HTML Formatter only needs the standard web platform — file picker access for the inputs you choose to load, and optionally clipboard access if you copy the result rather than downloading it. There is no microphone, camera, geolocation or background-permission request, because none of those are needed for the work the tool does.