Primary Key Finder Online - Free Browser Tool

Delimiterdetected: ","

Input CSVCSV

Best candidateorder_id

Best score100/100

Candidates10

Almost keys3

columns	score	unique	duplicates	reason
order_id	100	4 / 4	0	Unique and complete.
order_id + user_id	100	4 / 4	0	Unique and complete.
order_id + email	100	4 / 4	0	Unique and complete.
order_id + sku	100	4 / 4	0	Unique and complete.
user_id + sku	100	4 / 4	0	Unique and complete.
email + sku	100	4 / 4	0	Unique and complete.
user_id	84	3 / 4	1	Almost key; duplicates need review.
user_id + email	84	3 / 4	1	Almost key; duplicates need review.
email	80	3 / 4	1	Almost key; duplicates need review.
sku	60	2 / 4	2	Almost key; duplicates need review.

Primary key candidates CSVCSV

columns,score,unique,total,duplicate_rows,blank_rows,reason
order_id,100,4,4,0,0,Unique and complete.
order_id + user_id,100,4,4,0,0,Unique and complete.
order_id + email,100,4,4,0,0,Unique and complete.
order_id + sku,100,4,4,0,0,Unique and complete.
user_id + sku,100,4,4,0,0,Unique and complete.
email + sku,100,4,4,0,0,Unique and complete.
user_id,84,3,4,1,0,Almost key; duplicates need review.
user_id + email,84,3,4,1,0,Almost key; duplicates need review.
email,80,3,4,1,0,Almost key; duplicates need review.
sku,60,2,4,2,0,Almost key; duplicates need review.

Tip: use samples, upload, copy, download, and send-to actions inside the workspace where available.

What is Primary Key Finder?

Primary Key Finder is a free, browser-based tool that helps you convert between formats. Find unique identifiers, composite keys, and almost-keys that fail due to blanks or duplicates. It's built for speed and privacy: Everything runs locally in your browser — your data is never uploaded to a server. No sign-up, no installs, and no daily limits.

How to use Primary Key Finder

1Paste your data into the input panel, or drag-and-drop a file (you can also load a built-in sample).
2Adjust the conversion options — delimiter, formatting, and field handling — to match your data.
3Review the result in the output panel and copy it or download it as a file.

Features

Auto-detects delimiters and structure
Round-trips cleanly between formats
100% client-side — no upload, fully private
Free with no account, no watermark, and no daily limit
Works on large inputs, limited only by your device's memory
Load a sample, then copy, download, or share your result

Common uses

Profiling an unfamiliar dataset before analysis
Quick one-off converter jobs without opening a heavy app
Preparing data before importing it elsewhere
Sharing a reproducible result with a teammate via a link

Used by

Data analysts
Researchers
Business analysts
Students
Data migration teams
Integration engineers

Examples

Example 1

Example source input

Source data with headers, fields, and nested values

Example converted output

Converted data ready to copy, download, or continue into another tool.

Example 2

Small data sample

data with two rows or records

Converted result

result output with the same fields preserved.

Example 3

Nested or multi-field input

Record with id, name, status, created_at, and nested metadata

Flattened or normalized output

Fields are preserved in the target format so the data can be reviewed or imported.

Example 4

Input with blanks

A record where one optional field is empty or null

Output with blanks preserved

The result keeps missing values explicit instead of silently inventing data.

Example 5

Export workflow

Data copied from an API response, spreadsheet, or database export

Ready-to-use export

Converted output that can be copied, downloaded, or sent to another DataXForge tool.

Common errors

Headers or keys are not consistent across records.
Delimiter, quote, or encoding settings do not match the source file.
Nested fields need flattening before the result works as a table.
Blank values are mistaken for zeros or real values instead of remaining explicit.

How it works

1Reads the data input in the browser.
2Maps fields into the target structure.
3Renders a preview and exportable output.

AI prompt for this task

Use this prompt when you want an AI assistant to explain or double-check the same job.

Act as a data assistant. Use the same goal as Primary Key Finder: convert this data and explain any assumptions.

Input:
[paste your data here]

Return the result, a short explanation, and any warnings about malformed, missing, duplicate, or sensitive values.

Recommended workflow

1
Prepare the input
Start with the source file or pasted payload, then confirm delimiters, headers, and field handling before conversion.
2
Run Primary Key Finder
Review the preview, copy or download the result, and keep everything local in your browser.
3
Next recommended tool
Join Key Analyzer: Compare two CSV tables and rank the safest join keys with duplicate and unmatched-rate diagnostics.
Open tool
4
Then continue with
Column Relationship Detector: Spot foreign-key candidates and 1:1 / 1:N relationships.
Open tool
5
Then continue with
Duplicate Analysis: Quantify exact and near-duplicates.
Open tool

Frequently asked questions

How do I use Primary Key Finder?: Paste or drop your data into the workspace, adjust the options to fit your data, then copy or download the result. Find unique identifiers, composite keys, and almost-keys that fail due to blanks or duplicates.
Is my data uploaded or stored anywhere?: No. Everything runs locally in your browser — your data is never uploaded to a server. Nothing is sent to a server, so it's safe to use with private or sensitive data.
Is Primary Key Finder free?: Yes — it's completely free with no account, no sign-up, no watermark, and no daily usage limits.
What's the maximum file size?: There's no hard limit imposed by the tool. Because processing happens in your browser, the practical ceiling is your device's available memory — most everyday files work instantly.
Do I need to install anything?: No installs and no extensions — it runs entirely in your web browser and even works offline once the page has loaded.

columns

score

unique

duplicates

blanks

reason

order_id

100

4 / 4

Unique and complete.

order_id + user_id

100

4 / 4

Unique and complete.

order_id + email

100

4 / 4

Unique and complete.

order_id + sku

100

4 / 4

Unique and complete.

user_id + sku

100

4 / 4

Unique and complete.

email + sku

100

4 / 4

Unique and complete.

user_id

3 / 4

Almost key; duplicates need review.

user_id + email

3 / 4

Almost key; duplicates need review.

3 / 4

Almost key; duplicates need review.

sku

2 / 4

Almost key; duplicates need review.

What is Primary Key Finder?

Examples

Example 1

Example source input

Source data with headers, fields, and nested values

Example converted output

Converted data ready to copy, download, or continue into another tool.

Example 2

Small data sample

data with two rows or records

Converted result

result output with the same fields preserved.

Example 3

Nested or multi-field input

Record with id, name, status, created_at, and nested metadata

Flattened or normalized output

Fields are preserved in the target format so the data can be reviewed or imported.

Example 4

Input with blanks

A record where one optional field is empty or null

Output with blanks preserved

The result keeps missing values explicit instead of silently inventing data.

Example 5

Export workflow

Data copied from an API response, spreadsheet, or database export

Ready-to-use export

Converted output that can be copied, downloaded, or sent to another DataXForge tool.

AI prompt for this task

Use this prompt when you want an AI assistant to explain or double-check the same job.

Act as a data assistant. Use the same goal as Primary Key Finder: convert this data and explain any assumptions.

Input:
[paste your data here]

Return the result, a short explanation, and any warnings about malformed, missing, duplicate, or sensitive values.

Recommended workflow

Prepare the input

Start with the source file or pasted payload, then confirm delimiters, headers, and field handling before conversion.

Run Primary Key Finder

Review the preview, copy or download the result, and keep everything local in your browser.

Next recommended tool

Join Key Analyzer: Compare two CSV tables and rank the safest join keys with duplicate and unmatched-rate diagnostics.

Open tool

Then continue with

Column Relationship Detector: Spot foreign-key candidates and 1:1 / 1:N relationships.

Open tool

Then continue with

Duplicate Analysis: Quantify exact and near-duplicates.

Open tool

Frequently asked questions

How do I use Primary Key Finder?

Paste or drop your data into the workspace, adjust the options to fit your data, then copy or download the result. Find unique identifiers, composite keys, and almost-keys that fail due to blanks or duplicates.

Is my data uploaded or stored anywhere?

No. Everything runs locally in your browser — your data is never uploaded to a server. Nothing is sent to a server, so it's safe to use with private or sensitive data.

Is Primary Key Finder free?

Yes — it's completely free with no account, no sign-up, no watermark, and no daily usage limits.

What's the maximum file size?

There's no hard limit imposed by the tool. Because processing happens in your browser, the practical ceiling is your device's available memory — most everyday files work instantly.

Do I need to install anything?

No installs and no extensions — it runs entirely in your web browser and even works offline once the page has loaded.