Line Ending Converter — LF, CRLF, CR
Detect and convert line endings between LF (Unix), CRLF (Windows), and CR (Classic Mac).
How it works
- 1Paste or type your text in the input field
- 2Click "Convert" — processing happens in your browser
- 3Copy the result or download as a text file
What to do next
About Line Ending Converter
Line Ending Converter is a web utility tool that runs in your browser. Detect and convert line endings between LF (Unix), CRLF (Windows), and CR (Classic Mac). The page you are reading is the same workspace you will use to do the work: pick a file or paste your input, choose the options that matter to you, and the tool produces the result on your device.
Line Ending Converter is shaped for the gap between "I'll do it by hand" and "I'll script it." When the job is small enough that automating it would take longer than doing it, but annoying enough to want a focused tool — that is the situation this page is built for.
Line Ending Converter runs the entire transformation inside your browser. The file is read by JavaScript running in the page, processed in-memory by standard browser APIs, and written back as a download. The browser is the runtime; the page is the interface. You can confirm what the tool does by opening the developer-tools Network tab during a run — the only requests are for the page's own static assets.
Architecturally, Line Ending Converter is a single-page client. The processing layer is standard browser APIs; the UI is a thin React shell on top. Inputs flow through the engine and the output is returned to the browser as a Blob you can save or copy. The 0 MB cap is the only hard limit and it exists to keep memory usage stable on every device.
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.
If you fit any of these descriptions, Line Ending Converter should slot cleanly into your workflow: community managers planning posts; product managers comparing options; researchers gathering quick references. The tool keeps the controls focused on what matters for each of these use cases.
Line Ending Converter returns the result as a download. If you are running multiple jobs, the output names will not collide as long as the input names differ. You can re-run with different settings as many times as you like; each run produces a fresh file with no caching trickery in between.
If your task needs more than one step, chain Line Ending Converter with BOM Detector & Remover, File Encoding Detector, and Text File Encoding Converter. Each tool produces output that is a clean input to the next, so multi-step workflows are just a matter of opening the next tool in a new tab and continuing.
Some notes on the design of Line Ending Converter. 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.
A short note on how Line Ending Converter came to look the way it does: every iteration started by watching how someone unfamiliar with the tool actually used it, then removing whatever got in their way. That is why the upload area dominates the screen, the run button is bigger than the secondary controls, and the result panel is unmissable when the job finishes.
Line Ending Converter 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.
Pro tip: Line Ending Converter 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.
Common gotchas worth flagging: the supported formats are listed in the upload area. The 0 MB ceiling is per-file, not per-session; you can run as many separate jobs as you like, but a single oversized input will be rejected on load.
Line Ending Converter 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
- 1Reach the Line Ending Converter page in your browser to begin.
- 2Drop a web utility file onto the upload area, or click to pick one from your device.
- 3Adjust the options to match what you need. Sensible defaults cover the most common case, so you can usually skip this step.
- 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.
- 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
- Run a fast accessibility check before publishing using Line Ending Converter.
- Preview how a result looks before deploying it.
- Validate a setting before circulating it to a team.
- Create a placeholder image for a wireframe.
- Audit a marketing page before launch.
- Pull a quick reference number for a status update.
- Run a one-off check during a meeting without context-switching.
- Generate a temporary asset for a social post.
- Sanity-check a webhook response while debugging.
FAQ
What are line endings?
Invisible characters that mark the end of a line. LF (\n) for Unix/Mac, CRLF (\r\n) for Windows, CR (\r) for Classic Mac.
Why do they matter?
Mismatched line endings cause git diffs, broken scripts, and display issues across operating systems.
How is detection done?
The tool counts CRLF, LF-only, and CR-only sequences to determine the dominant format.
Mixed line endings?
If multiple formats are detected, it reports "Mixed" and converts all to your target format.
Git and line endings?
Configure .gitattributes with core.autocrlf to handle line endings automatically in repositories.
Private?
Yes — conversion runs locally.
Can I use Line Ending Converter on documents that contain personal data?
Your file is processed inside your browser by standard browser APIs. The engine reads the file's bytes from your tab's memory, computes the result, and writes the result back into the tab. You can confirm what the page does by opening developer tools and watching the Network tab during a run — the requests you see are for the tool's static assets only.
What does the error message in Line Ending Converter mean?
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.
Is Line Ending Converter lossless?
Line Ending Converter is built to preserve quality wherever the underlying web utility 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 Line Ending Converter have an API?
Line Ending Converter 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.
Are there any usage limits on Line Ending Converter?
Inputs are capped at 0 MB per file, which keeps memory usage stable across phones, tablets and older laptops. You can run Line Ending Converter as often as you need; every run produces a full-quality result.
Why use Line Ending Converter instead of a paid online tool?
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. Line Ending Converter sits in between: free, instant, and private, but intentionally narrow in scope. For one-off jobs and the common web and productivity utility operations, it is usually the lowest-friction choice; for highly specialised work, a dedicated app is still the right answer.
Can Line Ending Converter run inside a corporate firewall?
Line Ending Converter 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.
Which browsers are supported by Line Ending Converter?
Line Ending Converter 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.
Can I use Line Ending Converter with formats other than the defaults?
The accepted formats are listed in the upload area on the tool itself. If your input is in a format that is not directly supported, convert it first using one of Favtoo's converter tools — every Favtoo converter outputs a file that is a clean input to the next tool in the chain.