How Does an ATS Filter Resumes?

The use of Applicant Tracking Systems is nearly universal among large organizations and increasingly common across companies of all sizes. According to Capterra, about 75% of recruiters rely on some type of recruiting or applicant tracking system during the hiring process. This trend is even more pronounced among major employers—Jobscan reports that more than 98% of Fortune 500 companies incorporate ATS platforms when screening applicants.

In short, if you’re applying for a job, especially at a well-known company, your resume will almost certainly be reviewed by an ATS before it reaches any human eyes.
An Applicant Tracking System (ATS) doesn’t “read” your resume the way a human does. It processes it.

Think of it as a fast, literal scanner trying to answer one question:

“Does this candidate match what the job description is asking for?”

To do that, it goes through a few key steps:

ATS software looks for specific words and phrases pulled from the job description.

These can include:

• Job titles (“Product Manager”, “Software Engineer”)
• Skills (“React”, “SQL”, “Project Management”)
• Certifications or tools

If your resume doesn’t include enough of these terms, it may never reach a recruiter — even if you’re a strong candidate.

👉 It’s not about stuffing keywords. It’s about speaking the same language as the role.

Tailor Your Resume for Each Application

Carefully match your resume to the language of the job description every time you apply. If the posting lists specific skills that you have—but usually leave off—make sure to add them before hitting “submit.” Rephrase your experience and skills to mirror the exact wording or tense used in the listing where it makes sense, even if it feels a bit repetitive or slightly awkward. The ATS isn’t grading your grammar; it’s matching patterns.

Whenever possible, avoid uncommon abbreviations unless they’re industry-standard (think “CPA” or “AWS”). Small tweaks like these can make the difference between your resume landing in a recruiter's hands or disappearing into the ATS void.

Before anything else, the ATS needs to understand your resume.

Clean, simple layouts help it parse information correctly:

• Clear section headings (Experience, Education, Skills)
• Standard fonts and formatting
• No tables, columns, or overly designed elements

If the system can’t read your resume properly, it can’t evaluate it.

Stick to basic, familiar formatting. Avoid graphics, charts, headers/footers, and multi-column layouts—most ATS read left to right, top to bottom, and will jumble or ignore anything outside that flow. Use standard headers (bold or all caps are fine), keep bullet points simple, and opt for a Word document (.doc or .docx) when possible, as it’s the safest bet for compatibility. PDFs are usually okay, but not always.

Remember: The simpler the formatting, the better your chances. Save the fancy resume design for when a human’s reviewing it. Instead, create a plain, ATS-friendly version to ensure your experience comes through loud and clear.

Choosing the Right Resume File Format

To maximize your chances of passing through an ATS, stick to standard file formats.

• Best choice: Microsoft Word (.doc or .docx) files are almost universally accepted and processed accurately by most ATS platforms.
• PDFs: While many modern ATS can handle PDFs, some older or custom systems still struggle with them. When in doubt, go with Word.
• Avoid: Formats like .jpg, .png, .odt, and rich text files (.rtf) — these can confuse the system or fail to process entirely.

Simple is safe: using a straightforward Word document ensures your resume’s structure and information are read correctly by the ATS.

Many ATS platforms assign a relevance score based on how well your resume aligns with the job.

They might consider:

• Keyword frequency and placement
• Years of experience
• Recency of roles
• Required vs. optional qualifications

Recruiters often see candidates ranked — not just listed.

The Hidden Problem: Outdated or Overly Demanding Job Descriptions

Here’s where things often go sideways: job descriptions aren’t always kept up to date, and they’re rarely as realistic as they should be.

• Many companies recycle old job postings, barely tweaking the requirements from one opening to the next.
• Over time, these descriptions morph into wish lists—jam-packed with “required” skills and experiences that few real candidates possess.

This creates a twofold issue:

1. Qualified candidates get screened out. If your experience is a 95% match but you’re missing a tool or certification that’s not actually necessary for success in the role, the ATS can filter you out before a human ever has a say.
2. Employers miss out, too. By being too rigid or overly ambitious with their lists, companies can inadvertently filter out talent that could thrive in the position. This leads to fewer applicants and sometimes even positions going unfilled.

When job descriptions are out of date or overloaded with requirements, both job seekers and hiring teams lose—qualified folks are invisible to the system, and organizations are left wondering where all the great candidates went.

Yes.

If your resume is missing critical requirements (like a required skill, certification, or experience level), the ATS may filter it out before a human ever sees it.

This doesn’t always mean you’re unqualified — just that the system didn’t recognize the match.

Why Does This Happen?

Here’s the wrinkle: job descriptions are often a moving target. Sometimes, they get packed with a laundry list of “required” skills that aren’t truly essential, or are left outdated for years. In fact, many employers admit they rarely update their job descriptions or only tweak them slightly.

Over time, this means job postings can become bloated with unnecessary or obsolete requirements. The result? Qualified candidates—people who could absolutely do the job—get screened out simply because their resumes don’t echo every keyword or exact skill listed.

It’s a lose-lose: candidates get overlooked, and employers risk missing out on great talent, accidentally creating their own skills shortage.

So, even if you’re a strong fit, missing just one keyword or matching term can mean your resume never makes it to a recruiter’s desk. The system simply doesn’t “see” your potential beyond what’s in its checklist.

An ATS is efficient, but it’s not intelligent in a human way.

It doesn’t understand:

• Potential
• Context
• Personality
• Communication skills

It matches patterns.

This means that sometimes, even highly qualified candidates don’t make it through the ATS filter. In fact, a study from Harvard Business Review found that 88% of employers felt that qualified, high-skilled candidates were screened out by an ATS simply because their resumes didn’t match the exact criteria in the job description. That percentage jumps to 94% for middle-skilled candidates.

So, while the ATS can help recruiters handle large volumes of applications quickly, it also has a tendency to overlook strong applicants who might use different wording or bring valuable, less obvious skills to the table.