The Invisible Internet Project (I2P) is a network layer that allows for censorship-resistant, peer-to-peer communication. Anonymous connections are achieved by encrypting the user’s traffic and sending it through a volunteer-run network of roughly 55,000 computers distributed around the world.

The Invisible Internet Project began in 2002 and has been active since that time.

How Does I2P Protect Me?

The server is hidden from the user and the user from the server. All I2P network traffic is internal to its network. Traffic inside the I2P network does not interact with the Internet directly. It is a layer on top of the Internet.Encrypted unidirectional tunnels are used between you and your peers to send traffic. No one can see where that traffic is coming from, where it is going, or what the contents are. Additionally I2P transports offers resistance to pattern recognition and blocking by censors. Because the network relies on peers to route traffic, location blocking is also reduced.

Distribution All traffic on the I2P network is encrypted. An observer cannot see a message’s contents, source, or destination. All traffic you route as a participant is internal to the I2P network, you are not an exit node. The network does not do distributed storage of its content ( like Freenet or IPFS). By participating as a node you are not storing content for anyone.If there are hidden services which you dislike, you may refrain from visiting them. Your router will not request any content without your specific instruction to do so.

Is Using I2P Dangerous?

The I2P network is an overlay network. There are no dangers in using an overlay network. If you are engaging activities that are illegal or dangerous on the internet, that does not change if you are using an overlay network.

Regarding using overlay networks, the Java implementation includes a “Strict Countries List” that is used to decide how I2P routers should behave within regions where applications like I2P may be limited by law. For example, while no countries that we know of prohibit using I2P, some have broad prohibitions on participating in routing for others. Routers that appear to be in the “Strict” countries will automatically be placed into “Hidden” mode.

When a router is placed into hidden mode, three key things change about its behavior. It will no longer publish a routerInfo to the NetDB, it will no longer accept participating tunnels, and it will reject direct connections to routers in the same country that it is in. These defences make the routers more difficult to enumerate reliably, and prevent them from running afoul of restrictions on routing traffic for others.

OPSEC Keep track of what profiles you maintain and what services you interact with no matter what network you use. Perform personal risk assessments. The I2P Java software ships with very good defaults for hops for privacy without sacrificing performance.

What About “De-Anonymizing” Attacks? Reducing anonymity is typically done by: A) identifying characteristics that are consistent across identities or B) identifying ephemeral characteristics of repeated connections.

Attacks on I2P in the past have relied on correlating NetDB storage and verification. By randomizing the delay between storage and verification, we reduce the consistency with which that verification can be linked to I2P activity, thereby limiting the utility of that data point. Attacks on software configured to work with I2P are out of scope for I2P to solve. When browsing I2P, hosting or using I2P services, it is the responsibility of the user to consider their threat model.

How Do I Connect To the I2P Network?

The core software (Java) includes a router that introduces and maintains a connection with the network. It also provides a handful of applications and configuration options to get you started and personalize your experience.I2Pd is a C++ implementation of the I2P protocol. When using I2Pd you will need to edit configuration files, with Java I2P you can do it all within a user interface.

What Can I Do On The I2P Network?

The network provides an application layer that allows people to use and create familiar apps for daily use. Additionally, the network has its own unique DNS so that you can self host or mirror content on the network. The I2P network functions the same way the Internet does. The Java software includes a BitTorrent client, and email as well as a static website template. Other applications can easily be added to your router console.

What Is the Best OS To Use?

The I2P core software is cross platform. The best OS to use is the one that you feel most comfortable using.

Do I Have To, Or Should I Use I2P in Qubes or Whonix? Am I Not Safe If I Use Something Else?

This depends on your personal threat model. Generally speaking, I2P in Qubes or Whonix are very strong security measures. You can usually use the I2P software with a Firefox or Chromium browser without worry.

It is more important to exercise caution with who you communicate with and how. If you’re doing something that attracts the attention of people with the time and energy to carry out massive, scaled up attacks or sophisticated zero-day attacks, then something extremely thorough like Qubes is an option. On the other hand, if you’re just hosting your blog or surfing I2P sites, then chances are you’re fine just using the OS you’re most comfortable with. The real answer is conscientiousness, don’t say anything you’re not comfortable with somebody repeating.

I Can See My IP Address?

Yes, this is how a fully distributed peer-to-peer network works. Every node participates in routing packets for others, so your IP address must be known to establish connections. While the fact that your computer runs I2P software is public, nobody can see your activities in the network. For instance, you cannot see if a user behind an IP address is sharing files, hosting a website, doing research or just running a node to contribute bandwidth to the network.

Firewalled Status?

A firewalled I2P router can still access the I2P network. However, if you want to provide extra capacity to the network, it is necessary to open ports.Open I2P’s port on your modem, router and/or firewall(s) for better connectivity (ideally both UDP and TCP).For more information about Port Forwarding: https://portforward.com/

Browsing Functions in I2P

A properly configured browser supports accessing content on the I2P network ( I2P sites and services ) and accessing clearnet content via the outproxy service specified in the Hidden Services Manager of the I2P router.

Instruction for configuring a browser are outlined here: https://geti2p.net/en/about/browser-config .

There is also a Firefox based extension ( I2P in Private Browsing Mode ) that can be found in the the new experimental Windows installer, or can be added directly from here: https://addons.mozilla.org/en-US/firefox/addon/i2p-in-private-browsing/

Does It Matter What Browser Is Used To Access Content On the I2P Network?

Yes and no. Technically, you can use any browser that has support for proxies. However, some browsers are more secure than others. Also, depending on the browser, it may be more difficult to set up a proxy.

What Browser Should I Use For I2P on Android?

In principle, any browser works, but Privacy Browser is the easiest to set up because it has pre-configured proxy settings for I2P. Instruction can be found here: https://github.com/eyedeekay/Configuring-Privacy-Browser-for-I2P-on-Android#configuring-privacy-browser-for-i2p-on-android

Is It Possible To Install I2P Software on an iPhone?

This is currently not possible without increased effort. If you are tech savvy you can take a look at https://i2pd.readthedocs.io/en/latest/devs/building/ios/. Currently there is no official I2P app available.

What Does It Mean When I See That My I2P Router Needs To Be Integrated Into The Network?

An I2P router needs a few minutes to connect to the network. Sometimes it can take up to an hour.

How Can I tell If The I2P Proxy Is Ready?

You can go to 127.0.0.1:7657/tunnelmgr, if the status of “I2P HTTP Proxy” is green, the proxy is ready and you should be able to surf.

I Cannot Reach I2P Sites

If your router is running and you have shared clients and a browser configured, or are using I2P In Private Browsing Mode and see a proxy ready indicator, check the I2P project website using the link found in /home in the router console. If you can reach that site, then you know that your connection is good and browser is working. If you cannot reach a specific site, please realize that we cannot help you with that.

How Do I Activate the SAM Bridge?

To enable the SAM API: go too http://127.0.0.1:7657/configclients. Find the menu item called “SAM application bridge.” Select “Run at Startup” and press the small arrow to the right of the text.

How Come Router ‘shutdown’ Takes Several Minutes?

Because you are routing traffic for other peers. If you shutdown your router immediately, you interrupt their traffic.

Hi guys,

many services such as websites, git hosting providers, torrents, chats, forums, etc are available on I2P. But is there any Lemmy, Mastodon or other Fediverse/ActivityPub network on I2P? I am not talking about a proxy to clearnet Lemmy/Fediverse but a I2P Fediverse. Please let me know if they exist and where to find them.

sincerely, xxxb

This release of I2P, 2.13.0, has been focused on post-quantum support, performance improvements, and bug fixes that improve usability.

Since the 2.12.0 release (April 2026), development has focused on stronger encryption, better bandwidth management, network stability, and a more usable console.

Post-quantum protection is now fully available on the main transport (NTCP2), guarding against future “harvest now, decrypt later” attacks. The underlying cryptography library has been updated with constant-time operations prevent timing-based attacks. Legacy transport code (SSU1) has been fully removed.

Tunnels now have per-tunnel bandwidth limits, preventing any single tunnel from monopolizing your connection. The system is smarter about congestion.

Peer discovery and selection have been tuned for reliability. Floodfills are tracked more accurately.

The web interface now shows a world map of routers in search results for RouterInfos in the NetDB.

Containers now handle log rotation automatically, drop privileges properly, manage IP addresses correctly in containerized environments, and start up more reliably.

The BitTorrent client (i2psnark) reannounces faster after magnet links resolve, handles edge cases better, and cleans up bandwidth limiters on exit. The email client (Susimail) offers an experimental standalone build and removes old login code.

As usual, we recommend that you update to this release. The best way to maintain security and help the network is to run the latest release.

Copied from that other site, I'm not the person behind this.

Recently I was thinking about what I'm doing on internet. And I found out that all of my internet activity is basically just watching videos on youtube. So I thought "Why there isn't anonymous, private and free (as in freedom) youtube-like site on I2P?" and decided to do it myself.

First eepsite of this project: http://itubep.i2p

More you can read on project's github page: https://github.com/i2ptuber/itubep

Warning! Work heavily in progress.

Warning!!! Code is 100% AI slop, because I'm poor programmer.

Copied from that other site...

Independent researcher working on an I2P censorship measurement paper (English). Have some preliminary findings and an analysis framework in place. Looking to go deeper before submitting to arXiv.

Seeking collaborators for:

• Longitudinal tracking — baseline data collected, need ongoing observation for trend analysis

• Node reverse engineering — behavioral patterns identified, want to confirm technical details

• Protocol verification — TCP-level results done, want to add deeper handshake validation

Non-profit project, no funding. Co-authorship (2nd/3rd) based on contribution.

Interested? Reach me via PGP-encrypted email with your GitHub profile and a brief intro:

iasds.github.io

PGP: 1A60 9235 A475 39DF 6C4C C09B 822A 6DA9 E3BD 0612

Copied from reddit

I built an open-source Python tool that scans the I2P NetDB using nothing but vanilla i2pd floodfills. No patched binaries, no active probing — just parse the routerInfo files i2pd already writes to disk.

Repo: https://github.com/iasds/i2p-network-scanner

How it works

Run a few i2pd floodfill instances with different identities. Each covers a different DHT shard, so together they passively collect RouterInfo from most of the network. A single Python script parses the raw .dat files and extracts ident hashes, IPs, versions, caps flags, transports, and bandwidth tiers. Companion tools handle SQLite import, CLI queries, and GeoIP enrichment.

I ran a scan and published the results

5 floodfills, ~24 hours. The full analysis is in the repo:

• 17,541 known routers — 5,205 with public IPs, 12,336 behind NAT or firewalled

• 70% hidden is not a coverage gap — routers behind NAT simply don't include a host= field. That's I2P by design.

• 4,976 unique IPs across 111 countries

• Top countries: US (1,120), Russia (507), Germany (366), Canada (199), Netherlands (198)

• China has only 72 public nodes. Iran has 96.

• 0.9.68 dominates at 47% of routers, but only 11% of them publish an IP. Newer 0.9.69 (20% share) has 55% public rate.

• Java I2P is essentially extinct — nearly everything runs i2pd.

• 90 floodfills worldwide, concentrated in US, Russia, and Germany.

• Only 76 routers declare X-tier bandwidth (>2 MB/s).

Full report: I2P_NETWORK_ANALYSIS.md

If anyone has historical NetDB snapshots I'd love to compare trends over time. PRs welcome.

I've been wondering, is there a good way to find things on i2p like there is on tor? Like a search engine?

TEXT COPIED FROM REDDIT!

Hi everyone,

I want to share the idea I had for a hackaton.

Starting from the problem:

For ~30 years, discovery (of information or of people) has been mediated by a central index: search engines, recommenders....

Ranking is computed server-side, under rules the user can't inspect (think of Instagram or TikTok feed)

The idea to create a feed for a P2P network: convert messages into meaningful concepts through embeddings:

If each device can (a) run a competent embedding model locally and (b) reach other devices peer-to-peer, then relevance (semantic match) no longer needs a central index. It can be computed at the edge, by semantic distance, with no privileged ranking party.

In order to test, I developed a working prototype to pressure-test the idea rather than simulate it.

Each post is encoded into a embedding by a model running on the device (EmbeddingGemma-300M). A lightweight signed announcement (author + embedding) gossips peer-to-peer across a shared room; full bodies are pulled only for the bounded set a node actually admits. Each device ranks incoming posts against its own posts by cosine similarity and keeps a bounded local inbox.

There is no server, no account, no global ranking, the address space is meaning

Why could be potentially the basis for the agentic era?

The same substrate I presented lets AI agents discover each other: an agent publishes a need or an offer as an embedding, and agents whose profiles are semantically close respond.

The experiment it's fully open source (Apache-2.0) code, the complete threat model, and the architecture docs are all public.

Ordinal reddit post. https://www.reddit.com/r/ipfs/comments/1ucvu5e/semantic_routing_through_rag_to_create_a_p2p/

XNS is the eXile Name System. It makes Monero the only source of truth. Each XNS name is a result of a 0.01 XMR burn transaction with the desired name and owner public Ed25519 key.

Now it can be used as the name system of I2P.

Why would you use it all of a sudden? Because currently, there is no safe names in I2P. Unless you use direct b32.i2p addresses, which are not human memorable.

What's wrong with .i2p addresses? They are just entries on your own machine and on jump services. You have to trust those jump services if you share your .i2p address with others and expect reliability. Think of it as .local/.lan names your network router resolves.

While with XNS, once you claim a XNS name, as long as Monero stands, your name will be yours and no one can take it from you.

Read more about it on https://xns.rocks/docs For I2P specific articles, read https://xns.rocks/docs/xns-and-i2p/xns-on-i2p Source code: https://xns.rocks/exilens/xns Matrix channel: #xns:xns.rocks | https://matrix.to/#/#xns:xns.rocks

XNS is made for the Internet of free people. I believe I2P is the only reliable way.

IslandChat, a free chat site with roulette now supports I2P!

You can access it with this link: http://ji34zyv5j526gflnyw5jym45zt6uvk7x6x2vq3ccjyaq7ntjt4ka.b32.i2p

Be aware, HTTPS is required for video chat to work in browsers, so this link will redirect you to the actual address with HTTPS enabled. Once there, your address book will have 2 addresses; one is the HTTP with redirect, and the other is the real address. If you try accessing the real address without HTTPS, it won't work.

Javascript is also required for the site to function.

Happy chatting!

I installed I2P on a Linux laptop. For the moment I'd prefer not to have I2P to start automatically as system service. The installation guide says that after installation I can simply run i2prouter start, which starts the service and opens the router console on my browser; I've configured the router.

Question 1: what's the best way to shut down router and service, when I need to? The guide above says I can use the command i2prouter stop; but I also see buttons on the browser console and on the tray on the taskbar.

Question 2: I've also noticed that sometimes after i2prouter start I get asked again to configure the router. How do I make sure the configuration is saved once and for all?

Unfortunately I didn't find anything about these specific points in guides or FAQs.

Thanks for helping!

This update focuses on critical stability improvements, memory management, and the initial infrastructure for I2P integration. We've also addressed several UI bugs and search logic inconsistencies to provide a smoother user experience.

New Features

• I2P Integration: Added the foundational configuration infrastructure for I2P, including a dedicated UI settings panel and registration within the options dialog
• JDK 26: Updated to JDK 26 bundled runtime
• Telluride Build 44: Latest Telluride Video Downloader improvements

🛠️ Bug Fixes & Stability

• Memory Leak Prevention: Implemented bounds on previously unbounded image and icon caches to stop excessive memory consumption
• Crash Fix: Resolved a specific crash that occurred when users pasted non-video URLs into the search bar
• Linux Improvements: Fixed persistent tray icon issues specifically for users on KDE Plasma (#845)
• Search Logic: Fixed the "Search Tools" filter and overhauled the logic to ensure all search filters now work independently and accurately
• I2P Configuration: Fixed I2PPaneItem return value for applyOptions to ensure settings are saved correctly

📈 UI/UX Refinements

• Speed Accuracy: Fixed a calculation error in the Peers Tab; download/upload speeds are now correctly converted from bytes/s to KB/s for easier reading

I've finally installed the I2P (java) software, and even though I'm not actively using I2P yet, I'm very happy to contribute bandwidth to the network.

I'd like to understand more the difference between I2P and I2Pd. Is it just different software for the same purpose? So it seems from the FAQ here: "I2Pd is a C++ implementation of the I2P protocol. When using I2Pd you will need to edit configuration files, with Java I2P you can do it all within a user interface."

I'd be happy to hear about user experiences on both. Was I2Pd much more difficult to set up? Is it more than just a software difference? Has anyone noticed better stability or other differences with either one?

Thanks for everone's help! 🙏

Warning: AI slop, but might be somewhat interesting to anyone wanting an overview.

Hey guys,

I am running an I2Pd-Node on my raspberry pi somewhere in Germany and I am loving it so far.

About the ethical implications I am at peace with me, because I know, that it's not possible to allow good things without allowing the bad things too.

Sometimes I am a little bit concerned about, what a paranoid government could do. Technically - I don't know what I am forwarding. And since we're not talking about providing an exit-node (to clear-net) like we usually do with Tor, the risk should be greatly reduced as well.

As far as I know, theoretically this scenario could be possible: A large marketplace for illegal stuff appears within the I2P-Network. Law enforcement connects to it and tries to identify the "hops" between them and the marketplace (one by one) and my node is one of it. I know how crazy this sounds. Not very likely, but not impossible as well.

How do you think about this? Are there any recommended precautions you could take to prove you're not the criminal, if LE surprisingly knocks at your door?

~sp3ctre

People's websites get pummeled by LLM companies scraping the web. I bet they don't use nor scrape I2P though. Would using eepsites be a remedy?

/etc/i2pd/i2pd.conf contains number of listening ports configuration (actually 10 or more when you look for "port"). Which ones should I open in firewall so other people can connect my node? Excluding ones that are meant for management of my node. I manage the node only locally.

So far I have only open/forwarded one port, one that is set a few lines below the line "## Port to listen for connections" that certainly allows relaying traffic for other I2P peers per the http://127.0.0.1:7070/ traffic stats.

Services HTTP Proxy	Enabled
SOCKS Proxy	Enabled
BOB	Disabled
SAM	Enabled
I2CP	Enabled
I2PControl	Disabled

From that other site...

‐-----------

Hi everyone,

I’ve been working on a project called OTRv4+ – an OTRv4 client that adds post‑quantum cryptography to every layer of the protocol. It’s a single‑file Python app (with three small C extensions) that runs on IRC, supports I2P/Tor, and even runs on a phone via Termux.

Why post‑quantum?

If a quantum computer breaks X448 tomorrow, your past and future messages are still protected. The key exchange uses Triple X448 + ML‑KEM‑1024, authentication uses Ed448 ring signatures + ML‑DSA‑87, and the ratchet brace key rotates via fresh ML‑KEM‑1024 at every DH epoch. All symmetric crypto uses SHA‑3 / AES‑256‑GCM, which are quantum‑resistant at the symmetric level.

What makes it different?

· No liboqs – I used OpenSSL 3.5+ native FIPS 203/204 providers for ML‑KEM and ML‑DSA.

· Single‑file Python (~12k lines) – the whole protocol is in one file to make auditing easier.

· 224 tests – covering ratchet torture, state forks, wire format fuzzing, and everything in between.

· Runs on Termux – I tested it on my phone with I2P on Libera.Chat.

Comparison with Signal PQXDH

Signal’s PQXDH adds ML‑KEM to the handshake but explicitly says “Authentication in PQXDH is not quantum‑secure”. OTRv4+ uses ML‑DSA‑87 to make authentication post‑quantum as well – at the cost of losing PQ deniability (a known open problem). I think it’s a worthwhile trade‑off for IRC where deniability is less critical.

If you want to try it:

· Git clone: https://github.com/muc111/OTRv4Plus

· Requires Python 3.9+, OpenSSL 3.5+, and a C compiler.

· Works on Termux, Linux, probably other Unix‑likes.

· Supports I2P, Tor, and clearnet with auto‑detection from the hostname.

Feedback / Contributions

I’d love to get your thoughts – issues, pull requests, or just a “hey, this works on my setup”. If you’re interested in a commercial license for proprietary use, please open an issue with the label commercial-license.

Cheers!

From that other site.

‐-------------------------------

Hey guys, I've been building open-source launcher for i2pd that makes getting started with I2P as simple as possible.

What it does:

• Bundles a forked i2pd build with a preconfigured browser

• One-click start — no manual configuration needed

• Native .gn TLD support (custom domain resolution built into the i2pd fork. .gn and .i2p sites working in i2p network)

• Auto-downloads browser

Current state:

First public beta (v0.1.0 "Ronin"), Windows only for now. It works but expect rough edges — bug reports are very welcome.

GitHub: https://github.com/vialolis/GrayNet

Linux and Android ports are planned. Feedback appreciated.

Hey folks!

I just learned about I2P and already tested it successfully with I2Pd on my debian PC.

But I want to support the network 24/7 so I need to set it up on my raspberry pi 4 and I plan to use it from LAN.

So I installed it like described in the documentation for debian (https://docs.i2pd.website/en/latest/user-guide/install/#linux).

I changed my config via sudo nano /etc/i2pd/i2pd.conf and edited some things like this:

[http]
enabled = true
address = 0.0.0.0
port = 7070

[httpproxy]
enabled = true
address = 0.0.0.0
port = 4444

and I restarted with sudo systemctl restart i2pd

I am using the I2Pd-Firefox-Bundle and I changed the Firefox-settings (Settings -> Network Settings) to this:

(pointing to my raspberry pi)

.i2p-Sites are working well so far, but I am not able to open the webconsole with this configuration. I try to open it with http://192.168.178.26:7070/ but I only get host mismatch.

What am I doing wrong?

Thanks in advance!

~sp3ctre

Edit:

A solution has been found with nginx:

On the Pi:

sudo apt update
sudo apt install nginx

Followed by:

sudo nano /etc/nginx/sites-available/i2pd

Edit to:

server {
    listen 8080;
    server_name _;

    location / {
        proxy_pass http://127.0.0.1:7070/;
        proxy_set_header Host localhost;
    }
}

Enable the file:

sudo ln -s /etc/nginx/sites-available/i2pd /etc/nginx/sites-enabled/

Deleted the nginx-default-site

sudo rm /etc/nginx/sites-enabled/default