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Head / tail (first & last lines)

Keep just the first or last N lines of your text. Works on a pasted block or on a file you drop in.

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Open Head / tail (first & last lines) and you get an answer straight away, with no account to create. You will find it under Web & network, with Lines to JSON array and Wrap lines in HTML tag for the neighbouring cases.

How to use it

  1. Open the tool — no signup or install needed.
  2. Enter your input or adjust the available options.
  3. Get your result instantly, then copy or download it.

Frequently asked questions

What does Head / tail (first & last lines) do?

Keep just the first or last N lines of your text. Works on a pasted block or on a file you drop in.

When would I actually use this?

Getting usable data out of something that was never meant to be parsed: pulling every address out of a pasted thread, turning a column of lines into a JSON array or an SQL IN clause, renaming a hundred identifiers from snake_case to camelCase in one pass.

What is the most common mistake?

Trusting an extraction to be exhaustive. A pattern that catches every address in the sample will still miss the one wrapped across a line break, the one written with a display name, and the one an email client turned into a link — count what came out against what you expected before you use the list.

How is Head / tail (first & last lines) different from Lines to JSON array?

They sit next to each other but answer different questions: Lines to JSON array is the one to open when you need it to turn a list of lines into a JSON array of strings. Drop a file in rather than pasting it — it is read in your browser and never uploaded. Pick whichever matches what you're starting from — both are free.

Is there a tool for the next step?

Wrap lines in HTML tag is the closest one after this: Wrap each line in an HTML tag of your choice (e.g. li, p, td).

Where do the figures come from?

Extraction runs on patterns, not on a parser: it recognises the common shapes of an address, a URL or an IP rather than validating them against their specification. That is the right trade for a paste, and the wrong one for input you are about to store.

Further reading

All guides →
ExplainerSemicolon, Tab, Pipe: Choosing a Delimiter That Survives the TripWhy the reader's language decides the delimiter, what the converter does to the quoting when you switch, what the sep= first line really is, and the count of quoted cells on the same export written five ways.ComparisoncamelCase, snake_case, kebab-case: Which One, and Why You Rarely Get to ChooseThe conventions are not taste. A hyphen is the minus operator, so kebab-case cannot be an identifier in most languages - which is exactly why CSS and URLs use it. Plus the acronym round-trip that silently corrupts names, and the rule that fixes it.ExplainerBig O Notation for Beginners: O(1), O(n), O(n squared), and O(log n) ExplainedBig O describes how an algorithm's work grows as input grows. Here is what O(1), O(n), O(n squared), and O(log n) mean and why the difference matters.ExplainerWhat Is UTF-8 and Unicode? Code Points, Byte Encoding, and Why UTF-8 WonUnicode assigns every character a code point; UTF-8 encodes those code points in one to four bytes. Here is how it works and why it beat the alternatives.ExplainerHow Subnet Masks Work: CIDR, Network Bits, and Usable HostsUnderstand how a subnet mask splits an IP address into network and host parts, what /24 means, and how to count usable hosts.How-toHow to Read Binary and Convert It to Decimal and HexLearn how binary place values work and convert binary to decimal and hexadecimal by hand, with clear worked examples.