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Peeking Inside a Database Backup Without a Database

A Supabase backup landed in your downloads and you just need to check one table. This browser tool parses the dump and shows you the data — no restore, no upload.

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Abdullah Tarar

Apr 05, 2026 ·2 min read ·1 views
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It is a familiar small emergency: a Supabase or PostgreSQL backup file is sitting in your downloads, and you need to answer one question — is the data in there? The orthodox route is absurd for the task: install Postgres, create a database, run pg_restore, connect a client, query. The Supabase Backup Visualizer replaces all of it with: open the file in your browser.

How It Works

PostgreSQL dumps store table data in COPY blocks — COPY table (columns) FROM stdin; followed by tab-separated rows. The visualizer parses exactly that structure:

  • Every COPY block in the file is detected, and its table name and column list extracted.
  • A dropdown lists every discovered table with its row count — public.messages (1,204 rows).
  • Pick a table and the data renders as a clean grid with sticky column headers, row hover highlighting, and smooth two-directional scrolling.
  • Postgres \N markers render as proper null cells, and every value is safely escaped before display.

It accepts .backup, .sql, and .txt files, and gives clear status feedback — including an honest "No tables found in this file" when a dump uses a format it can't read.

The Non-Negotiable Feature

Backups contain production data — real users, real emails, real everything. Uploading one to a random "online SQL viewer" is a data breach with extra steps. This tool reads the file with the browser's FileReader API and nothing else: no upload, no server, no network request. The backup never leaves your machine, which is the only acceptable design for this job.

The Experiment

Like several of our experiments, this one probes how much real tooling fits in a single dependency-free HTML file. The answer here: enough to verify a backup, inspect a table, or recover a value — in the time the orthodox route spends installing prerequisites.

Use it: Supabase Backup Visualizer.

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