A Dataedo alternative for the data dictionary part

ErdDocs generates the data dictionary and the ER diagram from a schema you already have. That is the document you hand to an auditor, a client or a new teammate. It is built in your browser, which is where the schema stays. Dataedo is a data catalog that teams install and license by the year. Paste a schema dump below and compare the output with what you came for.

What ErdDocs does that Dataedo does not

Feature	ErdDocs	Dataedo
Runs in a browser tab, nothing to install or host	✓ Yes	Partly: a hosted option through sales; otherwise you install and host it
No repository database to set up	✓ Yes	× No: a SQL Server or Azure SQL database
Free to try without a time limit	✓ Yes	× No: a 14-day trial or a proof-of-concept license
Reads Prisma and ORM models	✓ Yes	× No: no ORM files among its sources
The schema stays on your machine	✓ Yes	Partly: in its repository database
One payment, no renewal	✓ Yes	× No: annual plans only

Dataedo is a trademark of its owner. The table reflects Dataedo’s own pages as of November 2026.

Dataedo needs a repository database on SQL Server or Azure SQL before the first document. You install and host it yourself unless you arrange hosting with its sales team, and it is licensed by the year from $18,000. It reads no ORM files. ErdDocs reads a pasted dump or ORM models in a browser tab, keeps the schema on your machine and costs $9 once.

When the request is one document

“Send us the schema documentation” from an auditor or a client is a request for a document. The whole task is to export, paste and print. It is done before a trial would finish installing.

Your schema

CREATE TABLE clients (
    id        bigserial PRIMARY KEY,
    name      varchar(160) NOT NULL,
    industry  varchar(80)
);
COMMENT ON TABLE clients IS 'Companies we deliver projects for';

CREATE TABLE projects (
    id         bigserial   PRIMARY KEY,
    client_id  bigint      NOT NULL REFERENCES clients(id),
    code       varchar(20) NOT NULL UNIQUE,
    started_on date        NOT NULL,
    closed_on  date
);
COMMENT ON COLUMN projects.code IS 'Short code used in invoices and folders';
COMMENT ON COLUMN projects.closed_on IS 'NULL while the project is active';

CREATE TABLE tasks (
    id          bigserial    PRIMARY KEY,
    project_id  bigint       NOT NULL REFERENCES projects(id),
    title       varchar(200) NOT NULL,
    estimate_h  numeric(6,2),
    done        boolean      NOT NULL DEFAULT false
);

CREATE TABLE timesheet (
    task_id   bigint        NOT NULL REFERENCES tasks(id),
    worked_on date          NOT NULL,
    hours     numeric(4,2)  NOT NULL,
    PRIMARY KEY (task_id, worked_on)
);
COMMENT ON TABLE timesheet IS 'Billable hours; one row per task per day';

CREATE TABLE clients (
    id        bigserial PRIMARY KEY,
    name      varchar(160) NOT NULL,
    industry  varchar(80)
);
COMMENT ON TABLE clients IS 'Companies we deliver projects for';

CREATE TABLE projects (
    id         bigserial   PRIMARY KEY,
    client_id  bigint      NOT NULL REFERENCES clients(id),
    code       varchar(20) NOT NULL UNIQUE,
    started_on date        NOT NULL,
    closed_on  date
);
COMMENT ON COLUMN projects.code IS 'Short code used in invoices and folders';
COMMENT ON COLUMN projects.closed_on IS 'NULL while the project is active';

CREATE TABLE tasks (
    id          bigserial    PRIMARY KEY,
    project_id  bigint       NOT NULL REFERENCES projects(id),
    title       varchar(200) NOT NULL,
    estimate_h  numeric(6,2),
    done        boolean      NOT NULL DEFAULT false
);

CREATE TABLE timesheet (
    task_id   bigint        NOT NULL REFERENCES tasks(id),
    worked_on date          NOT NULL,
    hours     numeric(4,2)  NOT NULL,
    PRIMARY KEY (task_id, worked_on)
);
COMMENT ON TABLE timesheet IS 'Billable hours; one row per task per day';

Your diagram appears here.

An agency-style projects schema; COMMENT ON texts fill the Description column.

FAQ

Is ErdDocs a full replacement for Dataedo?

No. ErdDocs does one of the jobs Dataedo covers: a schema you already have becomes a readable data dictionary and ER diagram, generated in your browser in seconds. For that job there is nothing to install, no repository database to set up and no annual license. If that one document is why you were quoted an enterprise contract, ErdDocs covers it for a single payment.

What does the price difference actually buy?

Dataedo is licensed by the year, and its published plans start at $18,000 a year. ErdDocs is $9 once, because the scope is narrower and there is no infrastructure behind it. Parsing happens in your browser, so there are no servers storing your metadata and nothing to subscribe to.

Does ErdDocs connect to my database like Dataedo does?

Deliberately not. You export the schema yourself with pg_dump --schema-only or mysqldump --no-data, and paste the file. That is one manual step per update. In exchange, the schema never leaves your machine. There is nothing to install, no credentials to hand over and no metadata repository to secure.

Can it document schema comments the way Dataedo shows descriptions?

Yes. COMMENT ON in PostgreSQL, inline COMMENT in MySQL and /// docs in Prisma all become the Description column of the generated dictionary, with nothing re-typed. ErdDocs has no in-app editing of those descriptions, by design. It treats the schema as the source of truth, so a description written once in the database shows up in every document generated from it afterwards.

Data dictionary generator: the tool this comparison is about.
Database documentation tools: other tools compared, including open source.
Lucidchart alternative: the same comparison for the diagramming side.