Artificial intelligence chatbot/ LLM (ChatGPT alternatives):

Company Website GitHub stars
OpenAssistant open-assistant.io
Leon getleon.ai
ChatRWKV twitter.com/BlinkDL_AI

AI code completion (Github CoPilot alternatives):

Company Website GitHub stars
FauxPilot github.com/fauxpilot/fauxpilot/wiki
YouCompleteMe ycm-core.github.io/ycmd

Team knowledge base (Notion alternatives):

Company Website GitHub stars
AppFlowy appflowy.io
AFFiNE affine.pro

Internal tools (Retool alternatives):

Company Website GitHub stars
Appsmith appsmith.com
ToolJet tooljet.com
ILLA illacloud.com
Windmill windmill.dev
Openblocks openblocks.dev

Web analytics (Google Analytics alternatives):

Company Website GitHub stars
Matomo matomo.org
Umami umami.is
Plausible plausible.io
OpenWebAnalytics openwebanalytics.com

Note-taking/ Knowledge management (Evernote alternatives):

Company Website GitHub stars
Joplin joplinapp.org
Logseq logseq.com
SiYuan b3log.org/siyuan/en
Notesnook notesnook.com

Company blogs/ newsletters (WordPress alternatives):

Company Website GitHub stars
Ghost ghost.org

Blogging platform/ Personal website builder (Medium alternatives):

Company Website GitHub stars
WriteFreely writefreely.org
btw btw.so

Newsletters (ConvertKit alternatives):

Company Website GitHub stars
listmonk listmonk.app

Static website generator:

Company Website GitHub stars
Hugo gohugo.io
Jekyll jekyllrb.com
Astro astro.build
11ty 11ty.dev
Zola getzola.org

Website builder (Wix, Strikingly, Webflow alternatives):

Company Website GitHub stars
Silex silex.me
DoTenX dotenx.com
Webstudio webstudio.is

Icons (Noun Project alternatives):

Company Website GitHub stars
Font-Awesome fontawesome.com
feather feathericons.com
Tabler-Icons tabler-icons.io
Bootstrap icons.getbootstrap.com
RemixIcon remixicon.com

Collaborative design tool (Figma alternatives):

Company Website GitHub stars
Penpot penpot.app
Radix Primitives radix-ui.com
Plasmic plasmic.app
Quant-UX quant-ux.com

Online forms (Typeform alternatives):

Company Website GitHub stars
Formbricks formbricks.com

Session replay and analytics (Fullstory alternatives):

Company Website GitHub stars
highlight highlight.io

Content Management System/ CMS (Contentful alternatives):

Company Website GitHub stars
Strapi strapi.io
Payload payloadcms.com
Webiny webiny.com

Log management (Papertrail alternatives):

Company Website GitHub stars
Graylog graylog.org

To-do app:

Company Website GitHub stars
super-productivity super-productivity.com

Community management:

Company Website GitHub stars
Discourse discourse.org
Flarum flarum.org
crowd.dev crowd.dev

Kanban board (Trello alternatives):

Company Website GitHub stars
WeKan wekan.github.io
Focalboard focalboard.com
Kanboard kanboard.org
Planka planka.app

Social network/ Micro-blogging (Twitter alternatives):

Company Website GitHub stars
Mastodon joinmastodon.org
HumHub humhub.com
Elgg elgg.org

Ticket management (Zendesk, Freshdesk alternatives):

Company Website GitHub stars
Zammad zammad.com
Peppermint peppermint.sh

Scheduling tool (Calendly alternatives):

Company Website GitHub stars
Cal.com cal.com

Smart spreadsheet (Airtable alternatives):

Company Website GitHub stars
NocoDB nocodb.com
Luckysheet dream-num.github.io/LuckysheetDocs
APITable apitable.com
Grist getgrist.com

Team communication (Slack, Discord alternatives):

Company Website GitHub stars
Rocket.chat rocket.chat
Mattermost mattermost.com
Zulip zulip.com
Element element.io
Spacebar spacebar.chat
RelatedChat relatedcode.com

Live chat (Intercom alternatives):

Company Website GitHub stars
Chatwoot chatwoot.com

User authentication (Auth0 alternatives):

Company Website GitHub stars
Keycloak keycloak.org
SuperTokens supertokens.com
Logto logto.io

Digital search experience (Algolia alternatives):

Company Website GitHub stars
Typesense typesense.org

Backend-as-a-Service (Firebase alternatives):

Company Website GitHub stars
Supabase supabase.com
Appwrite appwrite.io
Nhost nhost.io

Customer data platform/ CDP (Segment alternatives):

Company Website GitHub stars
Jitsu jitsu.com
Company Website GitHub stars
Dub dub.sh

Online store builder (Shopify alternatives):

Company Website GitHub stars
Medusa medusajs.com
Vue Storefront vuestorefront.io
Sylius sylius.com
Presta prestashop-project.org
Bagisto bagisto.com
Litekart litekart.in

Password manager (1Password alternatives):

Company Website GitHub stars
Bitwarden bitwarden.com (https://github.com/bitwarden/clients)[]
Passbolt passbolt.com (https://github.com/passbolt/passbolt_api)[]
Padloc padloc.app (https://github.com/padloc/padloc)[]

Email delivery (Mailgun, SendGrid alternatives):

Company Website GitHub stars
Postal docs.postalserver.io (https://github.com/postalserver/postal)[]

Usage-based billing (Stripe, Chargebee alternatives):

Company Website GitHub stars
Lago getlago.com (https://github.com/getlago/lago)[]

File uploader:

Company Website GitHub stars
Uppy uppy.io (https://github.com/transloadit/uppy)[]

Notification infrastructure:

Company Website GitHub stars
Novu novu.co (https://github.com/novuhq/novu)[]
ntfy ntfy.sh (https://github.com/binwiederhier/ntfy)[]
Gotify gotify.net (https://github.com/gotify/server)[]
Apprise hub.docker.com/r/caronc/apprise (https://github.com/caronc/apprise)[]

API development (Postman alternatives):

Company Website GitHub stars
hoppscotch hoppscotch.io (https://github.com/hoppscotch/hoppscotch)[]
Insomnia insomnia.rest (https://github.com/Kong/insomnia)[]

Programmatic videos:

Company Website GitHub stars
Remotion remotion.dev (https://github.com/remotion-dev/remotion)[]

Data warehouse (Snowflake alternatives):

Company Website GitHub stars
Databend databend.rs (https://github.com/datafuselabs/databend)[]

Annotation:

Company Website GitHub stars
doccano doccano.herokuapp.com (https://github.com/doccano/doccano)[]

Feature management/ Feature flag:

Company Website GitHub stars
Unleash getunleash.io (https://github.com/Unleash/unleash)[]
Flagsmith flagsmith.com (https://github.com/flagsmith/flagsmith)[]
Flagr openflagr.github.io/flagr/ (https://openflagr.github.io/flagr/#/)[]
FeatBit featbit.co (https://github.com/featbit/featbit)[]

Product analytics (Mixpanel, Amptitude alternatives):

Company Website GitHub stars
PostHog posthog.com (https://github.com/PostHog/posthog)[]

Video conferencing (Google Meet, Skype alternatives):

Company Website GitHub stars
Jitsi Meet jitsi.org (https://github.com/jitsi/jitsi-meet)[]
Element Call call.element.io (https://github.com/vector-im/element-call)[]

Personal cloud (Dropbox alternatives):

Company Website GitHub stars
Nextcloud nextcloud.com (https://github.com/nextcloud/server)[]

Business intelligence (Tableau, Looker, Power BI alternatives):

Company Website GitHub stars
Metabase metabase.com (https://github.com/metabase/metabase)[]

Platform-as-a-Service/ PaaS (Heroku, Netlify, Vercel alternatives):

Company Website GitHub stars
Dokku dokku.com (https://github.com/dokku/dokku)[]
CapRover caprover.com (https://github.com/caprover/caprover)[]
Coolify coolify.io (https://github.com/coollabsio/coolify)[]
Kubero kubero.dev (https://github.com/kubero-dev/kubero)[]

Unified Communication Platform & Telephony API (Twilio alternatives):

Company Website GitHub stars
Fonoster fonoster.com (https://github.com/fonoster/fonoster)[]

Bug tracking/ Error tracking (Sentry alternatives):

Company Website GitHub stars
Bugzilla bugzilla.org (https://github.com/bugzilla/bugzilla)[]

Invoicing:

Invoice Ninja invoiceninja.com (https://github.com/invoiceninja/invoiceninja)[]
Crater crater.financial (https://github.com/crater-invoice/crater)[]
SolidInvoice solidinvoice.co (https://github.com/SolidInvoice/SolidInvoice)[]

Graph database:

Company Website GitHub stars
JanusGraph janusgraph.org (https://github.com/JanusGraph/janusgraph)[]
Memgraph memgraph.com (https://github.com/memgraph/memgraph)[]

Vector database:

Company Website GitHub stars
Milvus milvus.io (https://github.com/milvus-io/milvus)[]
Weaviate weaviate.io (https://github.com/weaviate/weaviate)[]
activeloopai/deeplake activeloop.ai (https://github.com/activeloopai/deeplake)[]
CozoDB cozodb.org (https://github.com/cozodb/cozo)[]

Time-series database:

Company Website GitHub stars
Prometheus prometheus.io (https://github.com/prometheus/prometheus)[]
QuestDB questdb.io (https://github.com/questdb/questdb)[]
OpenTSDB opentsdb.net (https://github.com/OpenTSDB/opentsdb)[]
KairosDB kairosdb.github.io (https://github.com/kairosdb/kairosdb)[]

Document signing (DocuSign alternatives):

Company Website GitHub stars
Documenso documenso.com (https://github.com/documenso/documenso)[]

Workflow automation (Zapier alternatives):

Company Website GitHub stars
Automatisch automatisch.io (https://github.com/automatisch/automatisch)[]
Activepieces activepieces.com (https://github.com/activepieces/activepieces)[]

Project Management (Asana, JIRA alternatives):

Company Website GitHub stars
Plane Plane.so (https://github.com/makeplane/plane)[]
Leantime leantime.io (https://github.com/Leantime/leantime)[]

Personal finance (Empower Personal Wealth alternatives):

Company Website GitHub stars
Ghostfolio Ghostfol.io (https://github.com/ghostfolio/ghostfolio)[]

CRM (Salesforce, Hubspot alternatives):

Company Website GitHub stars
Twenty Twenty.com (https://github.com/twentyhq/twenty)[]

Criteria

  1. Product is open-source and repo is actively being maintained.
  2. It is a product (not a library) and ideally has a popular closed-source alternative.
  3. Repo has at least 100 stars on GitHub.

Contributing

Looking for contributors to add missing startups/ projects. Please submit a PR (the products are listed in descending order by number of GitHub stars) or feel free to DM @deeptivchopra.