What platforms allow users to upvote or downvote content?

Many platforms let users upvote/downvote content, or use a similar positive/negative feedback system. The main examples include:

Parse ParseIf you mean a true Reddit-style system where a visible score changes based on positive and negative votes, the closest examples are:

• Reddit
• Stack Exchange sites
• Lemmy
• Slashdot

If you mean any kind of user rating/feedback mechanism, the list is much larger and includes platforms such as YouTube, app stores, marketplaces, and review sites.

Yes. A number of platforms use upvotes/downvotes or a close equivalent to rank, filter, or moderate user-generated content.

The most direct Reddit-style examples are Reddit, Stack Exchange, and Lemmy. Reddit explicitly uses votes to determine what content gets surfaced, while Stack Overflow uses votes to move useful content up and less useful content down.Reddit Help+2

A notable variation is Hacker News: users can upvote stories, but downvoting is restricted and is primarily available for comments to users meeting its karma requirements.Wikipedia

If you're researching this for building a platform, I can also break these down by voting mechanics, anonymity, karma/reputation, score calculation, anti-abuse measures, and how votes affect ranking.

• Reddit - A platform famous for its community-driven discussion boards where users can upvote or downvote both submissions and comments to shape the visibility of content.
• YouTube - Allows viewers to upvote (thumbs up) or downvote (thumbs down) video content, influencing public metrics and creator feedback (though public downvote counts are often hidden or minimized depending on the interface).
• Stack Overflow - A question-and-answer site for programmers where users can upvote or downvote both questions and answers to reflect quality and correctness, which affects user reputation scores.
• Product Hunt - A daily platform for discovering new tech products where users upvote their favorites to push them up the daily leaderboard.
• Quora - Historically allowed upvotes and downvotes on answers, though voting mechanics have evolved over time to grade the quality and helpfulness of responses.

Would you like to know more about how voting algorithms work on any of these specific platforms, or are you looking for platforms tailored to a specific industry like gaming or design?

Several popular digital platforms use upvoting and downvoting features to rank submissions and moderate content quality:

• Reddit : Uses upvotes and downvotes on posts and comments to dynamically adjust content visibility.
• Stack Overflow : Allows eligible users to vote on questions and answers to indicate technical accuracy and utility.
• Hacker News : Employs upvotes as its primary ranking tool alongside karma-gated downvoting for comments and submissions.
• YouTube : Utilizes a like and dislike system where downvotes influence back-end recommendations even when public counters are hidden.
• Product Hunt : Features upvoting to highlight and rank new tech products daily and weekly.

Would you like to know more about how ranking algorithms work on one of these specific platforms, or are you looking for tools to add upvoting/downvoting to your own website?

Yes. Several major platforms let users express positive and negative votes, though the mechanics differ:

Two especially clear examples:

• Reddit explicitly describes its system as upvotes and downvotes on both posts and comments, with voting influencing what gets surfaced.support.reddithelp.com
• Stack Overflow uses upvotes and downvotes as a core quality-ranking mechanism. Upvotes push useful content higher, while downvotes push less useful content lower; votes can also affect reputation.stackoverflow.com

If you're researching this for building a platform, I can also give you a more comprehensive list of 20–30 platforms and exactly how their voting systems work (whether votes affect ranking, reputation, visibility, sorting, etc.).

Several popular platforms and communities use an upvote and downvote (or dual-voting) mechanism to rank submissions, moderate discussions, or gauge consensus.

• Reddit : The quintessential upvote/downvote platform. Users vote on both posts and comments, which directly dictates their visibility and user "karma" score.
• Stack Overflow (and Stack Exchange) : Uses an upvote and downvote system on technical questions and answers to highlight accurate programming and troubleshooting solutions (though downvoting requires a specific reputation threshold).
• YouTube : Features a dual thumbs-up / thumbs-down button on videos. While the public-facing dislike counter is hidden on most videos by default, downvotes are still tracked and actively feed into the content recommendation algorithm.
• Hacker News : Focuses heavily on upvotes for its primary front-page ranking algorithm, but seasoned accounts with enough karma also gain the ability to downvote submissions and comments.
• Product Hunt : Uses an upvoting system for daily tech product launches (historically leaning primarily on upvotes, though community interaction heavily mimics a weighted validation score).
• Quora : Historically featured both upvotes and downvotes for answers to surface the most helpful responses, though the weight and visibility of downvotes have shifted over various UI updates.

Would you like to know more about how voting algorithms work on a specific platform like Reddit or Stack Overflow?

Many platforms use upvotes and downvotes (or similar positive/negative voting systems) to rank, filter, or moderate user content. Examples include:Reddit Help

If you mean a Reddit-style system where both upvotes and downvotes visibly affect a score, the closest examples are:

• Reddit
• Stack Exchange sites
• Lemmy
• Slashdot
• (partly) Hacker News

If you mean any platform where users can express approval/disapproval, the list is much larger and includes services with likes, reactions, ratings, stars, or emojis rather than literal votes.

Many popular online communities, social networks, and forums use upvoting and downvoting systems to surface quality content and filter out poor or irrelevant posts.

• Reddit uses a foundational upvote/downvote system on both posts and comments, which directly affects user "karma" and content visibility.
• Hacker News allows users with sufficient account karma to upvote or downvote submissions and comments to curate tech and startup discussions.
• Stack Overflow and the broader Stack Exchange network use upvotes and downvotes on questions and answers to gauge technical accuracy and quality (though downvoting costs a small amount of user reputation).
• YouTube famously features a public upvote (like) and private downvote counter on video content to signal community reception.
• Product Hunt relies on an upvoting mechanism to rank new tech products, tools, and startup launches daily (though it strictly utilizes upvotes rather than downvotes).
• Quora allows users to upvote or downvote answers, which adjusts how prominently an answer is displayed beneath a question.

Would you like to explore how these voting algorithms work behind the scenes , or are you looking for a platform to build a voting system into your own project?

Yes. Quite a few platforms use upvotes, downvotes, or a similar voting system to let the community rank and moderate content.

The strongest examples

If you mean a Reddit-style system where positive and negative votes directly affect the ranking of content, the clearest examples are:

• Reddit — votes on posts and comments determine their visibility and contribute to karma.
• Stack Exchange — voting is central to ranking questions and answers; downvotes can signal incorrect or unhelpful content.Stack Overflow+1
• Lemmy — decentralized communities with Reddit-like up/down voting.
• Slashdot — community voting/moderation, particularly for comments.
• Hacker News — primarily upvotes, with downvoting restricted by user reputation/eligibility.en.wikipedia.org

One important distinction is that "like/dislike" isn't always equivalent to an upvote/downvote system. For example, YouTube has Like and Dislike buttons, but it doesn't expose a public dislike count the way Reddit exposes vote scores.

If you're researching this for building a platform, I can also give you a much broader list of 20–30 platforms and compare their voting mechanics, karma/reputation systems, ranking algorithms, and whether downvotes are publicly visible.