USPS Address Formatter
Address Cleaner is a free USPS address formatter that turns a messy list of addresses into a clean, consistent one. Paste your addresses, and it fixes the capitalization, applies the standard USPS street suffix abbreviations, and splits every line into street, unit, city, state, and ZIP — giving you back tidy postal block text or a CSV table. Nothing is uploaded. Every address is parsed inside your browser, so your customer list never leaves your device and never touches a validation server.
Paste your addresses one per line above, pick Block text or CSV, then tap Clean addresses. Capitalization is fixed, street suffixes are standardized, and each line is split into components — all on your device, nothing uploaded.
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Use the free Address Cleaner →What Is a USPS Address Formatter?
A USPS address formatter takes an address written any old way — all lowercase, all caps, "Street" spelled out here and "st." abbreviated there — and rewrites it in the single consistent style the U.S. Postal Service uses. That means proper capitalization, the official two-letter street suffix abbreviations, a two-letter state code, and the city/state/ZIP in their standard positions. It is a formatting step, not a lookup: Address Cleaner standardizes how an address is written, but it does not check whether the address is real or deliverable, and it never contacts an external address-validation API.
How to Clean and Format Addresses
- Open capsuletools.app/address-cleaner/.
- Paste your addresses into the box, one address per line. Commas between the street, city, and state help the parser split them accurately.
- Choose your output: Block text for ready-to-print postal blocks, or CSV table for spreadsheet columns.
- Optional — open Options to force all-uppercase (the USPS machine-sorting standard) or to expand suffixes to full words (Street) instead of abbreviating them (St).
- Tap Clean addresses, then Copy the result or Download it as a .txt or .csv file.
Lines that don't look like an address are skipped and counted, so a stray note or blank row won't corrupt your output. Everything runs the moment you tap the button — there is no upload step and no waiting on a server.
USPS Street Suffix Abbreviations Reference
The Postal Service defines one official abbreviation for every street suffix. Address Cleaner applies the full dictionary automatically; here are the most common ones (toggle Expand in Options to go the other way, from the abbreviation back to the full word):
| Suffix | USPS | Suffix | USPS |
|---|---|---|---|
| Street | ST | Lane | LN |
| Avenue | AVE | Court | CT |
| Boulevard | BLVD | Place | PL |
| Road | RD | Terrace | TER |
| Drive | DR | Circle | CIR |
| Highway | HWY | Parkway | PKWY |
Directionals are standardized too — North becomes N, Southwest becomes SW — and secondary-address designators such as Apartment, Suite, and Floor are shortened to Apt, Ste, and Fl.
Block Text vs. CSV Output
Block text gives you the classic two-line mailing format — the delivery line (house number, street, and any unit) on top, then City, ST ZIP underneath — ready to paste onto an envelope, label, or letter. CSV table instead splits every address into Street, Unit, City, State, ZIP columns with a header row, so you can download it and open it in Excel or Google Sheets. Use CSV when you need to split an address into street, city, state, and zip columns for a mail merge, CRM import, or shipping spreadsheet.
Your Addresses Never Leave Your Browser
Address lists are sensitive — they're your customers, your contacts, your recipients. Address Cleaner is built so that data stays yours: all parsing and formatting happens in JavaScript inside your own browser tab. Nothing is uploaded, nothing is sent to an address-validation service, and nothing is stored. Close the tab and the data is gone, and there's no account to create.
Frequently Asked Questions
What is address standardization?
Address standardization is the process of rewriting an address into a single consistent format — fixing capitalization, applying the official USPS street suffix abbreviations, and putting the city, state, and ZIP in their standard positions. It doesn't check whether the address is deliverable; it only makes the structure and spelling consistent so every address in a list looks the same.
What is the correct USPS address format?
The correct USPS address format is the delivery line — house number, directional, street name, standardized suffix, and any unit — on one line, then the city, two-letter state code, and ZIP or ZIP+4 on the next. For example, 123 N Main St Apt 4 above Springfield, IL 62704. USPS recommends all-uppercase with no punctuation for machine sorting, which you can produce with the Force uppercase option.
What are the USPS street suffix abbreviations?
USPS publishes a standard abbreviation for every suffix: Street becomes ST, Avenue becomes AVE, Boulevard becomes BLVD, Road becomes RD, Drive becomes DR, Lane becomes LN, Court becomes CT, and so on. Address Cleaner applies that full dictionary automatically, and can also expand abbreviations back to full words if you prefer Street over St.
How do I split an address into street, city, state, and zip columns?
Paste your addresses one per line, choose the CSV table output, and tap Clean addresses. The tool parses each line into separate Street, Unit, City, State, and ZIP columns and gives you a CSV you can download and open in Excel or Google Sheets. Using commas between the street, city, and state in your input makes the split most accurate.
How do I convert an address to proper case?
Paste an address typed in all caps or all lowercase and the formatter rewrites it in proper title case — capitalizing the first letter of each word while keeping the state code and directionals (N, SW) uppercase. Leave the Force uppercase option off for proper case, or turn it on for the all-uppercase style USPS recommends on envelopes.
Do you capitalize street names in an address?
Yes — street names are capitalized. In proper case each word of the street name is capitalized (Main St, Martin Luther King Jr Blvd); in the USPS machine-sorting standard the whole address is uppercase (MAIN ST). This formatter does either: it title-cases by default and switches to full uppercase when you enable Force uppercase.
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