OctosparkOctoSpark
Free tool

AI hashtag generator — viral tags for social media

Generate trending hashtags for Instagram, Twitter/X, and LinkedIn. On-device AI keeps your prompts private and produces platform-tuned tag sets in seconds.

Content description

Describe your post and the AI will generate platform-tuned hashtags.

Max 30 tags on Instagram.

330

AI engine

Models run in your browser — your prompts never leave your device.

The model loads on your first generation and is cached for later runs.

Platform tip

Instagram

Mix popularity tiers. Drop them in the first comment to keep captions clean.

Popularity legend

High — broad reach, heavy competition.

Medium — moderate reach, healthier engagement.

Low — niche tags with the highest engagement rate.

Pro tip

Mix popularity tiers in every post — pair a couple of high-volume tags with mid-tier ones and a handful of niche tags for the best reach-to-engagement balance.

Generate viral hashtags with on-device AI

Discover the right hashtags to lift your social media reach. Whether you post on Instagram, Twitter/X, or LinkedIn, the generator produces data-driven tag sets in seconds — no signup, no server round-trips.

Hashtag generation flow

  1. 1. Describe your content. Drop in a short summary of your post, image, or video.
  2. 2. Pick a platform. Twitter/X, Instagram, or LinkedIn — each has its own cap and tone.
  3. 3. Tune the count. Use the slider to set how many tags you want, up to the platform limit.
  4. 4. Generate and refine. Copy individual tags, copy them all, or download as a file.

Platform-specific hashtag strategies

Twitter/X hashtags

  • 1–3 hashtags maximum
  • Lean into trending topics
  • Use branded hashtags sparingly
  • Join active conversations

Instagram hashtags

  • 10–30 hashtags allowed
  • Mix popularity tiers
  • Combine niche and broad tags
  • Hide them in the first comment

LinkedIn hashtags

  • 3–5 professional tags
  • Industry and skill specific
  • Include company hashtags
  • Event hashtags for live posts

Hashtag best practices

Research before using

Check what content already lives under a hashtag. Make sure it aligns with your brand and has not been hijacked for unrelated topics.

Mix popularity tiers

Combine high-volume tags with medium and niche options. That gives you both reach and engagement quality.

Stay relevant

Only use hashtags that match the post. Off-topic tags hurt your engagement and credibility over time.

Track performance

Note which tags drive saves and shares. Refine your hashtag set based on what actually moves the needle.

Need more creative tools? Try OctoSpark.

Each free tool does one job. OctoSpark gives you the whole kit: posts and captions in your own voice, images and slideshows, and one calendar that publishes to every network and shows what performed.

Open the full sign-up page

No card needed. These tools stay free either way.

Frequently asked questions

How this tool works, what it cannot do, and what happens to what you put into it.

  • How does the AI hashtag generator work?

    It analyzes your content description and produces relevant hashtags tuned to the platform you select. Generation runs locally — Chrome built-in AI when available, otherwise Phi-3 via WebLLM in your browser.

  • How many hashtags should I use on each platform?

    Twitter/X: 1–3 hashtags work best. Instagram: 10–30 (we suggest 15–20). LinkedIn: 3–5 professional hashtags. The slider clamps to the platform you choose.

  • What do high, medium, and low popularity mean?

    High popularity tags reach huge audiences but face heavy competition. Medium offers a good reach-to-engagement balance. Low popularity tags are niche but tend to convert better with targeted audiences.

  • Can I edit the generated hashtags?

    Yes. Copy any tag individually, copy them all, or download as a text file. Treat the output as a starting point and refine to match your voice.

  • Is my data private?

    Yes. This tool does its work in your browser, so whatever you type, paste or upload stays on your device. Nothing is sent to our servers, which is also why it keeps working if you go offline after the page has loaded.

  • Where does the AI actually run?

    On your own machine. Chrome has a built-in model that the page uses when it is available, and otherwise the page downloads an open model such as Phi-4-mini and runs it on your GPU through WebGPU. Either way your prompt never leaves the device.

  • Which browsers are supported?

    Chrome gives the best experience because it can use its built-in model with no download. Any browser with WebGPU support, including recent Edge, Firefox and Safari, falls back to an open model instead. The first run downloads that model, so it is slower than the ones after it.

  • Is this really free?

    Yes. Every tool here is free with no account, no credit card and no usage cap. They exist so that the people who need our scheduling product find us, which only works if the tools are genuinely useful on their own.

  • Do I need an account?

    No. Open the page and use it. An account is only for OctoSpark itself, where you plan, schedule and publish a whole calendar rather than fixing one post at a time.

  • Can I use the output commercially?

    Yes. Anything you produce here is yours, including for client and commercial work. We claim no rights over it and we do not watermark it.