Conversion target survey · go2cs

The 100 Go modules everybody depends on

Ranked by how many other modules directly require them, from a full crawl of the Go module graph — then graded for whether a Go→C# transpiler can actually chew on them. The Go standard library is absent by construction: stdlib packages never appear in a go.mod.

source shape-of-go exported graph snapshot 2026-08-06 edges direct requires only, // indirect excluded source scan module zips from proxy.golang.org, 2026-08-28

2,638,112

modules in graph

9,443,537

direct dependency edges

~1,192,368

modules that import anything

180,094

ever imported (6.8%)

How to read the share column. It is the percentage of the ~1.19 million modules that declare at least one dependency — the population that could plausibly have imported the package. 54.7% of all Go modules declare no dependencies at all, so measuring against the full 2.6M would halve every number for no reason. Hover a bar to see both figures and the raw dependent count. Bars are square-root scaled: the distribution is a power law, and a linear bar renders everything past rank 5 invisible.

Four of these are already partly done. go2cs converts the Go standard library, and the standard library vendors a slice of four golang.org/x modules — so x/crypto, x/net, x/sys and x/text already exist under src/core/vendor. Only the vendored subset, though: 8 of 56 packages, 7 of 44, 1 of 14 and 4 of 63 respectively. Rows carry a go2cs n/N badge with the exact count.

Transpilation grade

Compact, pure Go, few dependencies

Start here. No cgo, no assembly, under ~20k lines, six or fewer direct dependencies.

Pure Go, larger or reflection-heavy

Fully transpilable, but big surface area or heavy reflection/unsafe. Good stress tests.

Runtime & platform substrate

Assembly with no pure-Go fallback, or //go:linkname into the runtime. Wants hand-written .NET shims, not transpilation.

cgo required to build

Core files import "C" with no build-tag escape. Not transpilable as-is.

Top 100 modules by direct dependents

Hover or focus a module path for its description, stars, license and a link to the repository — the module name itself opens the repository in a new tab. Hover a share bar for its raw counts. Click any column heading to sort.

#	Module	Dependents	Share of importers	Tier	kLOC	Deps	Signals
1	github.com/stretchr/testify — A toolkit with common assertions and mocks that plays nicely with the standard library v1.12.1 · go 1.17	346,205	29.04%	A	14.4	2	reflect×10
2	github.com/google/uuid — Go package for UUIDs based on RFC 4122 and DCE 1.1: Authentication and Security Services v1.6.0 · go —	146,611	12.30%	A	1.3	0
3	github.com/spf13/cobra — A Commander for modern Go CLI interactions v1.10.2 · go 1.15	137,951	11.57%	A	6.9	4
4	golang.org/x/crypto x — Go supplementary cryptography libraries Already in go2cs: 8 of 56 packages — the subset the Go standard library vendors, converted under src/core/vendor. v0.55.0 · go 1.25.0	133,882	11.23%	B	45.1	3	go2cs 8/56asm×15
5	google.golang.org/grpc — The Go language implementation of gRPC. HTTP/2 based RPC v1.83.2 · go 1.25.0	131,298	11.01%	B	123.4	24	reflect×34generics×5
6	google.golang.org/protobuf — Go support for Google's protocol buffers v1.36.12 · go 1.23	114,088	9.57%	B	281.0	2	reflect×154
7	github.com/pkg/errors — Simple error handling primitives v0.9.1 · go —	109,156	9.15%	A	0.5	0
8	github.com/sirupsen/logrus — Structured, pluggable logging for Go v1.10.2 · go 1.23	96,502	8.09%	A	3.4	2
9	golang.org/x/net x — Go supplementary network libraries Already in go2cs: 7 of 44 packages — the subset the Go standard library vendors, converted under src/core/vendor. v0.58.0 · go 1.25.0	94,915	7.96%	C	94.8	4	go2cs 7/44cgo·gatedasm×6linkname×4generics×7
10	github.com/spf13/viper — Go configuration with fangs v1.21.0 · go 1.23.0	89,030	7.47%	B	3.2	10
11	github.com/gin-gonic/gin — Gin is a high-performance HTTP web framework written in Go. It provides a Martini-like API but with significantly better performance—up to 40 times faster—thanks… v1.12.0 · go 1.25.0	87,344	7.33%	B	7.8	15
12	go.uber.org/zap — Blazing fast, structured, leveled logging in Go v1.28.0 · go 1.19	78,065	6.55%	A	9.3	4
13	gopkg.in/yaml.v3 — YAML support for the Go language v3.0.1 · go —	70,816	5.94%	A	11.3	0
14	github.com/prometheus/client_golang — Prometheus instrumentation library for Go applications v1.24.1 · go 1.25.0	70,524	5.91%	B	17.7	12	cgo·gated
15	k8s.io/apimachinery — Generic API machinery — schemes, serialization and shared types for Kubernetes v0.37.0 · go 1.26.0	67,827	5.69%	B	72.6	20	reflect×41generics×28
16	golang.org/x/sync x — concurrency primitives v0.22.0 · go 1.25.0	65,143	5.46%	A	0.6	0
17	github.com/joho/godotenv — A Go port of Ruby's dotenv library (Loads environment variables from .env files) v1.5.1 · go 1.12	63,668	5.34%	A	0.6	0
18	github.com/golang/protobuf — Go support for Google's protocol buffers v1.5.4 · go 1.17	63,567	5.33%	A	16.3	2	reflect×14
19	github.com/gorilla/mux — Package gorilla/mux is a powerful HTTP router and URL matcher for building Go web servers with v1.8.1 · go 1.20	62,308	5.23%	A	2.2	0
20	golang.org/x/sys x — Go packages for low-level interaction with the operating system Already in go2cs: 1 of 14 packages — the subset the Go standard library vendors, converted under src/core/vendor. v0.47.0 · go 1.25.0	61,998	5.20%	C	235.7	0	go2cs 1/14cgo·gatedasm×44linkname×17unsafe
21	k8s.io/client-go — Go client for Kubernetes v0.37.0 · go 1.26.0	60,488	5.07%	B	278.2	26	reflect×24generics×19
22	gopkg.in/yaml.v2 — YAML support for the Go language v2.4.0 · go 1.15	60,421	5.07%	A	9.6	1
23	github.com/lib/pq — Go PostgreSQL driver for database/sql v1.12.3 · go 1.21	58,657	4.92%	A	10.5	0
24	github.com/gorilla/websocket — Package gorilla/websocket is a fast, well-tested and widely used WebSocket implementation for Go v1.5.3 · go 1.12	56,912	4.77%	A	4.7	0
25	k8s.io/api — The canonical location of the Kubernetes API definition v0.37.0 · go 1.26.0	55,201	4.63%	B	437.2	2	reflect×60
26	gorm.io/gorm — The fantastic ORM library for Golang, aims to be developer friendly v1.31.2 · go 1.18	54,420	4.56%	A	15.5	3	reflect×30
27	github.com/google/go-cmp — Package for comparing Go values in tests v0.7.0 · go 1.21	53,071	4.45%	A	6.6	0	reflect×17
28	github.com/spf13/pflag — Drop-in replacement for Go's flag package, implementing POSIX/GNU-style --flags v1.0.10 · go 1.12	50,345	4.22%	A	6.3	0
29	golang.org/x/text x — Go text processing support Already in go2cs: 4 of 63 packages — the subset the Go standard library vendors, converted under src/core/vendor. v0.41.0 · go 1.25.0	47,490	3.98%	B	540.7	1	go2cs 4/63cgo·gatedreflect×18
30	golang.org/x/oauth2 x — provides support for making OAuth2 authorized and authenticated HTTP requests, as specified in RFC 6749 v0.36.0 · go 1.25.0	46,878	3.93%	A	6.6	1
31	github.com/go-sql-driver/mysql — Go MySQL Driver is a MySQL driver for Go's (golang) database/sql package v1.10.0 · go 1.24.0	43,731	3.67%	A	6.6	1
32	github.com/onsi/gomega — Ginkgo's Preferred Matcher Library v1.43.0 · go 1.25.0	38,035	3.19%	A	13.6	4	reflect×45
33	golang.org/x/exp x — Experimental and deprecated packages v0.0.0-20260824195058-e88cd73687aa · go 1.26.0	36,381	3.05%	B	24.7	4	cgo·gatedlinkname×1generics×8
34	github.com/fatih/color — Color package for Go (golang) v1.19.0 · go 1.25.0	35,400	2.97%	A	0.9	3
35	github.com/fsnotify/fsnotify — Cross-platform filesystem notifications for Go v1.10.1 · go 1.23	33,669	2.82%	B	4.5	1
36	golang.org/x/tools x — Go tooling: gopls, static analysis passes and AST/type utilities v0.49.0 · go 1.25.0	32,716	2.74%	C	155.5	6	linkname×4reflect×45generics×58
37	go.opentelemetry.io/otel — OpenTelemetry Go API and SDK v1.46.0 · go 1.25.0	32,250	2.70%	B	794.4	8	reflect×14
38	github.com/rs/zerolog — Zero Allocation JSON Logger v1.35.1 · go 1.23	32,182	2.70%	A	8.7	4
39	go.mongodb.org/mongo-driver — The Official Golang driver for MongoDB v1.17.9 · go 1.18	30,325	2.54%	B	93.6	10	cgo·gatedreflect×38
40	github.com/go-playground/validator/v10 — Go Struct and Field validation, including Cross Field, Cross Struct, Map, Slice and Array diving v10.30.3 · go 1.25.0	29,707	2.49%	B	40.7	7	reflect×32
41	sigs.k8s.io/controller-runtime — Repo for the controller-runtime subproject of kubebuilder (sig-apimachinery) v0.24.1 · go 1.26.0	29,258	2.45%	B	31.8	26	reflect×16generics×24
42	golang.org/x/time x — Go supplementary time packages v0.15.0 · go 1.25.0	29,098	2.44%	A	0.5	0
43	github.com/mattn/go-sqlite3 — sqlite3 driver for go using database/sql v1.14.50 · go 1.21	28,679	2.41%	D	6.7	0	cgounsafe
44	google.golang.org/api — Auto-generated Google APIs for Go v0.294.0 · go 1.25.0	28,428	2.38%	B	6067.5	18
45	github.com/golang/mock — GoMock is a mocking framework for the Go programming language v1.6.0 · go 1.11	27,754	2.33%	A	5.3	2	reflect×25
46	github.com/aws/aws-sdk-go — AWS SDK for Go v1 — end-of-support, superseded by aws-sdk-go-v2 v1.55.8 · go 1.19	27,723	2.33%	B	5935.0	1	reflect×30
47	go.opentelemetry.io/otel/trace — OpenTelemetry Go API and SDK v1.46.0 · go 1.25.0	26,889	2.26%	A	4.1	3
48	github.com/BurntSushi/toml — TOML parser for Golang with reflection v1.6.0 · go 1.18	26,023	2.18%	A	5.8	0
49	golang.org/x/term x — Go terminal and console support v0.45.0 · go 1.25.0	25,963	2.18%	A	1.4	1
50	github.com/davecgh/go-spew — Implements a deep pretty printer for Go data structures to aid in debugging v1.1.1 · go —	25,948	2.18%	A	2.1	0
51	github.com/golang-jwt/jwt/v5 — Go implementation of JSON Web Tokens (JWT) v5.3.1 · go 1.21	24,365	2.04%	A	2.8	0
52	gorm.io/driver/postgres — GORM PostgreSQL driver v1.6.2 · go 1.25.0	24,269	2.04%	A	1.3	2
53	github.com/jackc/pgx/v5 — PostgreSQL driver and toolkit for Go v5.10.0 · go 1.25.0	23,676	1.99%	B	39.0	6	reflect×13generics×8
54	github.com/aws/aws-sdk-go-v2 — AWS SDK for the Go programming language v1.45.1 · go 1.24	23,210	1.95%	A	12.6	1
55	github.com/urfave/cli/v2 — A declarative, simple, fast, and fun package for building command line tools in Go v2.27.7 · go 1.18	23,077	1.94%	A	9.8	4
56	github.com/go-chi/chi/v5 — lightweight, idiomatic and composable router for building Go HTTP services v5.3.2 · go 1.23	23,068	1.93%	A	4.4	0
57	go.opentelemetry.io/otel/sdk — OpenTelemetry Go API and SDK v1.46.0 · go 1.25.0	22,605	1.90%	B	6.7	10
58	github.com/gogo/protobuf — [Deprecated] Protocol Buffers for Go with Gadgets v1.3.2 · go 1.15	22,341	1.87%	B	448.4	0	reflect×93
59	sigs.k8s.io/yaml — A better way to marshal and unmarshal YAML in Golang v1.6.0 · go 1.22	22,127	1.86%	A	2.2	4
60	github.com/json-iterator/go — A high-performance 100% compatible drop-in replacement of "encoding/json" v1.1.12 · go 1.12	22,105	1.85%	B	9.8	5	unsafereflect×11
61	github.com/aws/aws-sdk-go-v2/config — AWS SDK for the Go programming language v1.33.1 · go 1.24	21,818	1.83%	B	7.3	8
62	github.com/redis/go-redis/v9 — Redis client for Go v9.22.0 · go 1.24	21,512	1.80%	B	61.8	6
63	github.com/dgrijalva/jwt-go — Archived JWT implementation, succeeded by golang-jwt/jwt v3.2.0+incompatible · go —	20,971	1.76%	A	1.8	0
64	gorm.io/driver/mysql — GORM MySQL driver v1.6.0 · go 1.18	20,825	1.75%	A	1.1	2
65	google.golang.org/genproto — Generated code for Google Cloud client libraries v0.0.0-20260825221802-da73d73af1c5 · go 1.25.0	20,323	1.70%	B	856.0	25	reflect×674
66	k8s.io/utils — Non-Kubernetes-specific utility libraries which are consumed by multiple projects v0.0.0-20260707023825-cf1189d6abe3 · go 1.25	20,249	1.70%	A	9.5	2	generics×5
67	github.com/mitchellh/mapstructure — Go library for decoding generic map values into native Go structures and vice versa v1.5.0 · go 1.14	20,194	1.69%	A	1.9	0
68	github.com/jmoiron/sqlx — general purpose extensions to golang's database/sql v1.4.0 · go 1.10	20,185	1.69%	A	3.0	3
69	github.com/labstack/echo/v4 — High performance, minimalist Go web framework v4.15.4 · go 1.25.0	19,770	1.66%	A	11.0	6
70	github.com/mitchellh/go-homedir — Go library for detecting and expanding the user's home directory without cgo v1.1.0 · go —	19,244	1.61%	A	0.2	0
71	github.com/onsi/ginkgo/v2 — A Modern Testing Framework for Go v2.32.1 · go 1.25.0	18,983	1.59%	B	22.5	10	generics×6
72	github.com/go-logr/logr — A simple logging interface for Go v1.4.4 · go 1.18	18,558	1.56%	A	3.0	0
73	k8s.io/klog/v2 — Leveled execution logs for Go, forked from golang/glog v2.140.0 · go 1.21	17,939	1.50%	A	7.6	1
74	github.com/miekg/dns — Full-featured DNS library in Go v1.1.73 · go 1.25.0	17,767	1.49%	B	22.3	3
75	github.com/charmbracelet/lipgloss — Style definitions for nice terminal layouts v1.1.0 · go 1.18	17,554	1.47%	A	5.9	6
76	github.com/prometheus/common — Go libraries shared across Prometheus components and libraries v0.70.1 · go 1.25.0	17,169	1.44%	B	9.1	13
77	github.com/go-redis/redis/v8 — Redis client for Go — v8 line, superseded by redis/go-redis v9 v8.11.5 · go 1.17	17,158	1.44%	A	15.6	4
78	github.com/docker/docker — The Moby Project - a collaborative project for the container ecosystem to assemble container-based systems v28.5.2+incompatible · go —	16,920	1.42%	D	197.3	0	cgoasm×1reflect×17
79	github.com/ethereum/go-ethereum — Go implementation of the Ethereum protocol v1.17.5 · go 1.24.0	16,546	1.39%	B	266.5	79	cgo·gatedasm×8linkname×1reflect×56generics×21
80	github.com/mattn/go-isatty — Reports whether a file descriptor refers to a terminal v0.0.24 · go 1.20	16,480	1.38%	A	0.2	1
81	github.com/swaggo/swag — Automatically generate RESTful API documentation with Swagger 2.0 for Go v1.16.6 · go 1.18	16,377	1.37%	B	8.3	7
82	github.com/olekukonko/tablewriter — ASCII table in golang v1.1.4 · go 1.21	16,330	1.37%	B	16.4	7
83	github.com/spf13/cast — safe and easy casting from one type to another in Go v1.10.0 · go 1.21.0	16,258	1.36%	A	1.7	1
84	gopkg.in/natefinch/lumberjack.v2 — lumberjack is a log rolling package for Go v2.2.1 · go 1.13	16,234	1.36%	A	0.6	0
85	github.com/charmbracelet/bubbletea — A powerful little TUI framework v1.3.10 · go 1.24.0	15,960	1.34%	B	4.8	8
86	github.com/rs/cors — Go net/http configurable handler to handle CORS requests v1.11.1 · go 1.13	15,765	1.32%	A	0.7	0
87	github.com/onsi/ginkgo — A Modern Testing Framework for Go v1.16.5 · go 1.16	15,413	1.29%	A	12.2	5
88	github.com/golang-jwt/jwt/v4 — Go implementation of JSON Web Tokens (JWT) v4.5.2 · go 1.16	15,328	1.29%	A	2.6	0
89	github.com/gofiber/fiber/v2 — Express inspired web framework written in Go v2.52.15 · go 1.20	15,210	1.28%	B	41.0	8	cgo·gatedunsafereflect×26
90	github.com/klauspost/compress — Optimized Go Compression Packages v1.19.2 · go 1.24	15,187	1.27%	B	48.7	0	asm×13
91	github.com/tidwall/gjson — Get JSON values quickly - JSON parser for Go v1.19.0 · go 1.23	14,751	1.24%	B	3.6	2	unsafe
92	github.com/ghodss/yaml — A better way to marshal and unmarshal YAML in Golang v1.0.0 · go —	14,737	1.24%	A	0.8	0
93	github.com/gorilla/handlers — Package gorilla/handlers is a collection of useful middleware for Go HTTP services & web applications v1.5.2 · go 1.20	14,580	1.22%	A	1.2	1
94	github.com/jinzhu/gorm — GORM v1 — superseded by gorm.io/gorm (v2) v1.9.16 · go 1.12	14,516	1.22%	B	7.0	7	reflect×17
95	golang.org/x/image x — Go supplementary image libraries v0.45.0 · go 1.25.0	14,045	1.18%	C	164.5	2	asm×1
96	modernc.org/sqlite — Package sqlite is a CGo-free port of SQLite/SQLite3. SQLite is an in-process implementation of a self-contained, serverless, zero-configuration, transactional… v1.57.0 · go 1.25.0	13,829	1.16%	B	1590.3	5	unsafereflect×24
97	go.uber.org/goleak — Goroutine leak detector v1.3.0 · go 1.20	13,673	1.15%	A	0.8	1
98	github.com/dustin/go-humanize — Go Humans! (formatters for units to human friendly sizes) v1.0.1 · go 1.16	13,657	1.15%	A	1.1	0
99	github.com/PuerkitoBio/goquery — jQuery-style HTML document traversal and manipulation v1.13.0 · go 1.25.0	13,653	1.15%	A	2.8	2
100	github.com/prometheus/client_model — Generated protocol buffer data model for Prometheus metrics v0.6.2 · go 1.22.0	13,597	1.14%	A	1.4	1

Collapsed by source repository — top 40

Major-version suffixes and submodules folded together, so aws-sdk-go-v2's 384 service modules and OpenTelemetry's 36 count once. Useful when the conversion unit is a repository rather than a module path.

#	Repository	Summed dependents	Share	Modules
1	github.com/stretchr/testify	346,205	29.04%	1
2	go.opentelemetry.io/otel	147,800	12.40%	36
3	github.com/google/uuid	146,611	12.30%	1
4	github.com/spf13/cobra	137,951	11.57%	1
5	google.golang.org/grpc	135,349	11.35%	7
6	golang.org/x/crypto	134,353	11.27%	2
7	gopkg.in/yaml	131,572	11.03%	3
8	github.com/aws/aws-sdk-go-v2	131,468	11.03%	384
9	google.golang.org/protobuf	114,097	9.57%	3
10	github.com/pkg/errors	109,156	9.15%	1
11	github.com/sirupsen/logrus	96,502	8.09%	1
12	golang.org/x/net	94,915	7.96%	1
13	github.com/spf13/viper	89,119	7.47%	2
14	github.com/gin-gonic/gin	87,344	7.33%	1
15	go.uber.org/zap	78,558	6.59%	2
16	github.com/prometheus/client_golang	70,585	5.92%	2
17	go.opentelemetry.io/collector	69,283	5.81%	100
18	k8s.io/apimachinery	67,827	5.69%	1
19	golang.org/x/sync	65,143	5.46%	1
20	github.com/joho/godotenv	63,668	5.34%	1
21	github.com/golang/protobuf	63,567	5.33%	1
22	github.com/gorilla/mux	62,308	5.23%	1
23	golang.org/x/sys	61,998	5.20%	1
24	github.com/open-telemetry/opentelemetry-collector-contrib	61,189	5.13%	355
25	k8s.io/client-go	60,488	5.07%	1
26	gorm.io/driver	59,814	5.02%	8
27	github.com/lib/pq	58,657	4.92%	1
28	github.com/gorilla/websocket	56,912	4.77%	1
29	k8s.io/api	55,201	4.63%	1
30	gorm.io/gorm	54,420	4.56%	1
31	github.com/google/go-cmp	53,071	4.45%	1
32	github.com/spf13/pflag	50,345	4.22%	1
33	github.com/golang-jwt/jwt	50,238	4.21%	3
34	golang.org/x/text	47,490	3.98%	1
35	golang.org/x/oauth2	46,878	3.93%	1
36	github.com/go-sql-driver/mysql	43,731	3.67%	1
37	cloud.google.com/go	41,603	3.49%	156
38	github.com/onsi/gomega	38,035	3.19%	1
39	github.com/urfave/cli	37,280	3.13%	3
40	google.golang.org/genproto	37,034	3.11%	5

Method & caveats

Where the ranking comes from

The shape-of-go project crawled index.golang.org for every module version published since April 2019, fetched each module's latest go.mod from proxy.golang.org, and parsed the require directives into a directed graph. This page reads that project's exported search.json — no part of the crawl was re-run.

Edges are direct requires only. Requires marked // indirect are excluded, so a count reflects modules that deliberately chose the dependency, not transitive pull-through.

Where the grades come from

Each module's latest release zip was downloaded and statically scanned. Counts exclude _test.go files and anything under testdata/, vendor/, or a _-prefixed directory — the same paths the Go toolchain ignores.

A cgo flag is only a blocker when an import "C" file would compile on a plain linux or windows build. Files behind an opt-in build tag (gssapi, journald, icu) or a minority-OS suffix are marked cgo·gated and do not affect the grade.

Where the descriptions come from

The hover text is each project's own repository description, resolved through deps.dev and GitHub — 86 of 100 verbatim. Thirteen were rewritten because the repository sets no description, or because the upstream text trailed off into a URL. One (golang.org/x/oauth2) uses its package doc comment.

Star counts are a rough popularity cross-check only. They disagree sharply with dependent counts for the golang.org/x mirrors, which almost nobody stars and almost everybody imports.

What go2cs already has

Coverage was read from go2cs/src/core/vendor, which mirrors the Go standard library's own src/vendor/golang.org/x tree. Converted package directories were matched against the full package list of each published module, so the counts are subset-of-module, not subset-of-vendor.

Nothing else in the top 100 is converted: src/core/vendor is the only third-party tree in the repository. The four marked modules stay on the list because the unconverted remainder is the overwhelming majority — x/crypto's ssh, acme, bcrypt and openpgp packages are all still open.

What to distrust

Counts are per module path. yaml.v2 and yaml.v3 rank separately though they are one project; the repository table above corrects for this.

A go.mod require is not an import. A module can require a dependency only one of its packages uses, and test-only dependencies count the same as production ones — which is most of why testify tops the list.

kLOC is raw line count of non-test .go files, blanks and comments included. Generated API surface (google.golang.org/api, aws-sdk-go) inflates it enormously.