Yosys is an open-source framework for synthesizing Verilog hardware designs into gate-level netlists. It supports scripted, extensible FPGA and ASIC synthesis workflows.
The open-source framework offers configurable synthesis passes, scripting, plugin support, and target-library mapping. It is free to use, but requires technical familiarity and its default HDL frontend has limited SystemVerilog support. No reliable public review-platform evidence was found.
This profile combines documented product information and independent evidence where available. It is not a hands-on test unless TechZella explicitly identifies one.
Yosys is an open-source framework for synthesizing RTL hardware designs. It reads Verilog, processes designs through configurable synthesis passes, and can write gate-level netlists. Users can run commands interactively, execute scripts, or extend the tool with additional passes.
The project is used in FPGA and ASIC flows, but it is not a complete graphical design suite. Users typically combine it with other tools for tasks such as place-and-route, simulation, or device programming. YosysHQ also offers Tabby CAD Suite, a commercial package with broader HDL and formal-verification features.
A quick way to understand who this product may suit, where its limits matter, and which facts are most relevant before you compare alternatives.
Hardware developers, researchers, and educators who need an inspectable, scriptable Verilog synthesis framework and can manage their own design flow.
Teams that require broad, industry-grade SystemVerilog or VHDL parsing from the outset may need the commercial Tabby CAD Suite or another tool. Yosys's built-in frontend supports only a limited SystemVerilog subset, and should evaluate alternatives such as AMD Vivado or Intel Quartus Prime instead.
Linux, macOS, Windows
7.8/10
These are the product-specific differences that may matter when deciding whether the software fits your workflow. They are based on documented evidence rather than a universal ranking.
These are documented constraints or practical friction points that may matter before you adopt the product.
The OSS package has Verilog and plugin-based support, while YosysHQ identifies its commercial suite as the option for broader SystemVerilog, VHDL, and SVA support.
Evidence source ↗A team may need a separate simulator or parser in its validation workflow.
Evidence source ↗Yosys is ISC-licensed free software. OSS CAD Suite is a free binary distribution of Yosys and related open-source digital-design tools.
Check current pricing →Commercial YosysHQ suite with expanded HDL and formal-verification features. The pricing page provides a calculator and directs prospective users to contact YosysHQ.
Check current pricing →Pricing may change. Verify current plans on the vendor's website.
Compare similar products directly, then see which alternatives may make more sense when your requirements differ.
| Decision factor | Yosys | AMD Vivado | Intel Quartus Prime |
|---|---|---|---|
| Core scope | Open synthesis framework for FPGA and ASIC design flows. | Integrated design suite for AMD adaptive SoCs and FPGAs, including synthesis, implementation, and verification or simulation tools. Source ↗ | Intel FPGA design software spanning design entry, synthesis, optimization, verification, and simulation. Source ↗ |
| Workflow interface | Command-line shell, synthesis scripts, and extensible passes. | GUI-based IDE and Tcl command or script interfaces. Source ↗ | An integrated FPGA development software suite with edition and device-specific workflows. Source ↗ |
| Pricing model | Yosys and OSS CAD Suite are free; commercial Tabby CAD pricing is handled through a calculator or vendor contact. | AMD describes tiered Vivado licensing, including free entry-level access and paid options. Source ↗ | Quartus Prime offers Pro, Standard, and Lite editions; Intel identifies the Lite edition as free. Source ↗ |
Only factors supported by the available research are shown. The comparison is descriptive, not a ranking.
These products address broadly similar requirements. The descriptions focus on documented reasons a buyer might compare them with Yosys.
| License | ISC |
|---|---|
| Deployment | Local installation or source build |
| Supported input | Extensive Verilog-2005; limited synthesizable SystemVerilog subset |
| Commercial HDL option | Tabby CAD Suite includes broader SystemVerilog, VHDL, and SVA support |
| OSS CAD Suite platforms | Linux x64 and ARM64; macOS x64 and ARM64; Windows x64 |
| API | C++ APIs for adding Yosys passes; command-line and script interfaces |
| Hosted REST API | Not documented in reviewed sources |
Verified installation, hosting, administration, or environment details that can affect implementation.
| Installation or hosting | Install locally from OSS CAD Suite binaries or build Yosys from source. The product is not described as a hosted SaaS service. Source ↗ |
|---|
Documented portability, standards, export, or switching considerations. No switching-cost score is shown unless the evidence supports one.
The documented workflow reads HDL and writes outputs such as Verilog netlists; the README also describes Yosys's internal RTLIL representation.
Evidence source ↗A proprietary editorial score based on product capabilities, usability, value, performance, support and user sentiment evidence.
The open-source framework offers configurable synthesis passes, scripting, plugin support, and target-library mapping. It is free to use, but requires technical familiarity and its default HDL frontend has limited SystemVerilog support. No reliable public review-platform evidence was found.
Methodology v1.0. The assessment weighs feature coverage (25%), ease of use (15%), value for money (20%), performance (15%), support (10%) and user sentiment (15%), using researched product evidence and verified review evidence where available. It is a TechZella editorial assessment, not a direct user-review average.
Key claims are linked to the sources used to verify them. This evidence record is separate from third-party user ratings.
TechZella evaluates software using documented product capabilities, pricing information, usability and value considerations, independent user evidence where available, and competitive context. The assessment is an editorial review, not a hands-on test unless one is explicitly identified. Our editorial assessment is based on 4 documented sources.
The project README describes Yosys as a framework for RTL synthesis tools and states that it is free software under the ISC license.
View source ↗Verified 2026-11-10The project README describes extensive Verilog-2005 support and a synthesizable SystemVerilog subset; the command reference distinguishes this from full support through Verific.
View source ↗Verified 2026-11-10The README describes synthesis scripts and extending the C++ codebase with additional passes.
View source ↗Verified 2026-11-10The OSS CAD Suite repository lists Linux x64 and ARM64, macOS x64 and ARM64, and Windows x64 distributions.
View source ↗Verified 2026-11-10YosysHQ's datasheet describes Verilog, SystemVerilog, VHDL, SVA, formal tools, and FPGA place-and-route among the suite's capabilities.
View source ↗Verified 2026-11-10The company imprint lists a Vienna address.
View source ↗Verified 2026-11-10Answers begin with the clearest available response, followed by the context that helps you act on it.
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