Open LEF files in your browser
A cell library as place and route tools see it, each cell's size, pins and blockages. Open one right here, every cell drawn with its pins named. Nothing leaves your device.
Or drop it anywhere on this page
What you'll see
Your layout opens with its cells down one side and its layers down the other.
- Every cell and what it places • Sharp at any zoom
- Layers by name • Hide one, show one alone or pull them apart in 3D
- Measure in microns • Find a cell, pin or label
- Export • PNG, SVG and the cell list as CSV
About LEF
Cadence's LEF is how place and route tools learn a cell library: the size of each cell, where its pins are and on which metal, and what routing has to go around, without the transistors inside.
A LEF holds a library's macros, each with its size, its class and its pins, with their direction, their use as signal, clock, power or ground and their shapes on each layer, and its obstructions. A technology LEF, often named .tlef, holds the process's side: each layer with its direction, pitch, width and spacing, and the vias between them.
Filepeek reads the file in your browser and draws each cell with its pins named on their shapes and its obstructions a click away, every cell listed beside it with its size, and the layers by the names and kinds the LEF gives them. A technology LEF shows its vias, and a LEF dropped with a DEF draws the design's cells.
Library Exchange Format
.lef • .tlef
Format
- MIME type
- text/x-lef
- Made by
- Cadence
Inside the file
- Macros
- Each cell with its size and class
- Pins
- Named, with their direction, use and shapes
- Obstructions
- Where routing can't go
- Layers and vias
- The process's stack, in a technology LEF
Opens in every browser
Browsers download LEF files, and place and route tools need installing. Filepeek opens them in Chrome, Edge, Firefox and Safari, cell libraries and technology LEFs alike.
- YouChromeOpens through Filepeek
- YouEdgeOpens through Filepeek
- YouFirefoxOpens through Filepeek
- YouSafariOpens through Filepeek
Questions
How do I open a LEF file?
Drop it on this page or choose Peek a LEF. It opens on its biggest cell, with every cell listed beside it and nothing to install.
What's the difference between a LEF and a technology LEF?
A cell library's LEF holds its cells, and a technology LEF, often .tlef, the process's layers and vias. Filepeek opens both, a technology LEF with its vias as its cells, and reads them together when they're dropped with a DEF.
Can I see which pin is which?
Yes. Each pin's name sits on its biggest shape, pins are drawn on layers of their own apart from the obstructions, and Search finds a pin by its name.
Can I measure a cell?
Yes. Its width and height show beside its name in the list, and Measure gives any distance in microns, snapping to corners and edges.
Can I open a DEF with its LEF?
Yes. Drop or pick them together. The DEF draws every cell it places from the LEFs, and names any cell they don't have.
Is my file uploaded?
No. The library opens inside your browser and never leaves your device.