Overview
EchoUploader is a tool that creates a permanent record proving a file existed at a certain time and who made it. You pick a file, and EchoUploader writes a timestamped proof of it to the Cardano blockchain. The file itself never leaves your device; only its fingerprint is written on-chain1.
EchoUploader is one of four products from EchoForge, a maker of small infrastructure tools for the Cardano ecosystem2. The fingerprint it records is a SHA-256 hash, a short string of characters that is unique to your exact file and changes completely if even one byte is altered. Because the hash is calculated inside your browser, EchoUploader can prove a file is unchanged without ever seeing its contents.
Key Features
- Your file stays private. EchoUploader calculates the file's fingerprint locally in your browser, so the file's contents never get uploaded anywhere; only the fingerprint and a timestamp are written on-chain1.
- A shareable proof page. Every anchor produces its own public web page tied to the blockchain transaction, where anyone can check the file's fingerprint and timestamp against the on-chain record1.
- Pay only the network fee. Anchoring a file costs just the Cardano transaction fee, roughly 0.17 ADA, priced in ADA through the Charli3 oracle with CoinGecko as a backup. There are no subscriptions or storage plans1.
- Two ways to anchor. Per mode is for an individual recording their own work; Org mode is for organizations that need to anchor files as a group1.
- Connects to wallets you already use. EchoUploader uses MeshJS, the common standard for letting Cardano wallets sign into apps, so you connect with your existing wallet1.
- Open-source contract. The smart contract behind the anchors is written in Aiken and published openly on GitHub, so anyone can read the code that records the proofs3.
What to Expect
A first-time visitor picks a file, connects a Cardano wallet, and confirms a small transaction to anchor the file's fingerprint. The whole step happens in the browser, and the file is never sent to a server. Afterward you get a link to a proof page you can share with anyone who needs to confirm the file's authorship and timestamp.
Records you anchor stay easy to find later, because EchoUploader keeps each file's name and fingerprint (not its contents) so you can search your past anchors. Each anchor also adds a point toward EchoID, EchoForge's account system that unlocks tier-based features across its products1. The interface is available in English, Simplified Chinese, Traditional Chinese, and Japanese. EchoForge lists EchoUploader as live, while noting on its public roadmap that broader network rollout and batch anchoring features are still in progress1.
