Topline is the intelligent content preview platform that outputs the first part of any file to stdout. Default 10 lines. Custom depths. Byte-level precision. We're redefining how the world previews data.
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Features
We took the core primitives of content previewing and turned them into a platform that gives you exactly the data you need—and nothing you don't.
Output a precise number of lines from the top of any file. Default is 10—the universally optimal preview depth. Override it to extract 1 line or 10,000. Your data, your depth.
Byte-level content extraction. Output the first NUM bytes of each file with binary precision. Supports multiplier suffixes from b (512) to Q (quintillions). Sub-line granularity, unlocked.
Suppress file name headers when previewing multiple files. Clean, uninterrupted output streams. Zero noise. Pure content. When your pipeline demands signal without decoration.
Always print file name headers, even for single-file previews. Full provenance traceability for every line of output. Because knowing where your data comes from is not optional.
Output all but the last NUM lines of each file. Negative indexing that trims from the bottom. Perfect for stripping footers, trailing metadata, and EOF garbage.
Use NUL as the line delimiter instead of newline. Designed for binary-safe pipelines and zero-terminated data streams. The flag that separates hobbyists from infrastructure engineers.
Pass any number of files. Topline previews each one sequentially with automatic headers between outputs. Multi-source preview orchestration, built into the core.
How It Works
Pass one or more file paths. Topline accepts unlimited FILE arguments or reads from stdin when no file is specified. Input is never the bottleneck.
Use LineSlice™ for line-based previews or ByteCut™ for byte-level precision. Default 10 lines. Negative numbers to trim from the end. Your call.
Enable SilentMode™ for clean multi-file output, VerboseHeaders™ for full provenance, or NullSplit™ for binary-safe delimiter handling.
The exact content you requested streams to standard output. No more, no less. Pipe it, redirect it, or consume it directly. Surgical precision, every time.
Pricing
The default 10-line experience
Custom LineSlice™ + multi-file
ByteCut™ + NullSplit™ + everything
Comparison
| Feature | Text Editors | grep + pipe | Topline |
|---|---|---|---|
| Line-based extraction | Manual scroll | Regex overhead | ✅ Native -n |
| Byte-level precision | ❌ | ❌ | ✅ ByteCut™ |
| Negative indexing | ❌ | Complex workaround | ✅ Native -n -NUM |
| Multi-file headers | Multiple tabs | Custom scripts | ✅ Automatic |
| Binary-safe delimiters | ❌ | ❌ | ✅ NullSplit™ |
| Pipeline composability | ❌ | Partial | ✅ First class |
Testimonials
"We used to open 200MB log files in Vim just to check the first 15 lines. Topline with -n 15 gives us the exact preview in under a millisecond. Our incident response time dropped by 60%."
"ByteCut™ is a game changer. We extract the first 128 bytes of every binary artifact in our build pipeline for fingerprinting. No other tool gives us byte-level precision with zero config."
"The negative indexing feature is criminally underrated. We use -n -5 to preview everything except the trailing metadata block on our data exports. Clean, automated, and reliable."
"SilentMode™ in a multi-file pipeline is the one feature I didn't know I needed. Topline previews 40 config files in a single pass with zero header noise. Pure content, nothing else."
"We evaluated every content extraction tool on the market. Topline's default 10-line preview is the most opinionated—and correct—default in developer tooling. The product-market fit is real."
Demo
Real output. Real first lines. Zero smoke and mirrors.
Live Activity
nginx.conf
2s ago
binary.dat
via ByteCut™
5s ago
export.csv
12s ago
core_dump.bin
15s ago
FAQ
After analyzing billions of file previews, we found that 10 lines captures the header, import block, and opening context of virtually any source file with near-perfect recall. It's not arbitrary—it's the statistical optimum for content preview density. We didn't choose 10. The data did.
Opening a file loads the entire thing into memory. Topline reads exactly what you need and stops. For a 2GB log file, that's the difference between crashing your editor and getting your answer in 0.1ms. This is not a convenience tool—it's an infrastructure primitive.
Yes. ByteCut™ (-c NUM) extracts the first NUM bytes of each file with binary precision. Supports multiplier suffixes: b for 512, K for 1024, M for 1048576, and so on up to Q. Byte-level content extraction is a first-class feature, not an afterthought.
With -n -NUM, Topline outputs all but the last NUM lines of each file. With -c -NUM, all but the last NUM bytes. This is TailDrop™ — precision trimming from the bottom. Perfect for stripping footers, checksums, or trailing metadata without touching the content you care about.
Never. Topline is a pure read operation. It extracts content to stdout and leaves your source files completely untouched. Immutable source integrity is a fundamental platform guarantee.
Join 6,800+ engineers who've already switched to Topline. Early access members get lifetime Pro pricing and custom LineSlice™ depths from day one.
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